{{about|this online encyclopedia itself|Wikipedia's home page|Main Page|Wikipedia's visitor introduction|Wikipedia:About|other uses|Wikipedia (disambiguation)}}

{{redirect|The Free Encyclopedia|other encyclopedias|Lists of encyclopedias}}

{{short description|Free online encyclopedia that anyone can edit}}



{{Use American English|date=June 2019}}

{{Use mdy dates|date=June 2019}}

{{Infobox website

| name = Wikipedia

| logo = [[File:Wikipedia-v2-logo.svg|150px|frameless|An incomplete sphere made of large, white, jigsaw puzzle pieces. Each puzzle piece contains one glyph from a different writing system, with each glyph written in black.]]<br />[[File:Wikipedia wordmark.svg|200px|The Wikipedia wordmark which displays the name Wikipedia, written in all caps. The W and the A are the same height and both are taller than the other letters, which are also all the same height.]]

| logocaption = The [[Wikipedia logo|logo of Wikipedia]], a globe featuring [[glyph]]s from several [[writing system]]s

| screenshot = Wikipedia Main Page.png

| screenshot_alt = Main page of the English Wikipedia

| caption = [[Main Page]] of the English Wikipedia on July 23, 2018

| collapsible = yes

| url = {{official url}}

| commercial = No

| type = [[Online encyclopedia]]

| registration = Optional<ref group=note>Registration is required for certain tasks such as editing [[protected page]]s, creating pages in the English Wikipedia, and uploading files.</ref>

| language = 303 languages

| num_users = [[List of Wikipedias#Grand total|>{{formatnum:{{#expr:{{NUMBEROF|ACTIVEUSERS|total}}-{{NUMBEROF|ACTIVEUSERS|mo}}-{{NUMBEROF|ACTIVEUSERS|ng}}-{{NUMBEROF|ACTIVEUSERS|cho}}-{{NUMBEROF|ACTIVEUSERS|kj}}-{{NUMBEROF|ACTIVEUSERS|mh}}-{{NUMBEROF|ACTIVEUSERS|ho}}-{{NUMBEROF|ACTIVEUSERS|ii}}-{{NUMBEROF|ACTIVEUSERS|aa}}-{{NUMBEROF|ACTIVEUSERS|mus}}-{{NUMBEROF|ACTIVEUSERS|hz}}-{{NUMBEROF|ACTIVEUSERS|kr}}}}}}]] active users<ref group=note>To be considered [[Special:ActiveUsers|active]], a user must make at least one edit or other action in a given month.</ref> and [[List of Wikipedias#Grand total|>{{formatnum:{{#expr:{{NUMBEROF|USERS|total}}-{{NUMBEROF|USERS|mo}}-{{NUMBEROF|USERS|ng}}-{{NUMBEROF|USERS|cho}}-{{NUMBEROF|USERS|kj}}-{{NUMBEROF|USERS|mh}}-{{NUMBEROF|USERS|ho}}-{{NUMBEROF|USERS|ii}}-{{NUMBEROF|USERS|aa}}-{{NUMBEROF|USERS|mus}}-{{NUMBEROF|USERS|hz}}-{{NUMBEROF|USERS|kr}}}}}}]] registered users<br/>1,145 administrators ([[English Wikipedia|English]])

| owner = [[Wikimedia Foundation]]

| author = [[Jimmy Wales]]<br/>[[Larry Sanger]]<ref name="Sidener"/>

| launch date = {{Start date and age|mf=yes|2001|1|15}}

| alexa = {{steady}} [https://www.alexa.com/siteinfo/wikipedia.org 5] {{nowrap|(Global, {{as of|2019|06|09|alt=June 2019}})}}

| oclc = 52075003

| current status = Active

| programming_language = [[LAMP (software bundle)|LAMP]] platform<ref name="roadchap">{{cite web |url= http://rogchap.com/2011/09/06/top-40-website-programming-languages/ |title= Top 40 Website Programming Languages |website= roadchap.com |author= Chapman, Roger |date= September 6, 2011 |accessdate= September 6, 2011 |deadurl= yes |archiveurl = https://web.archive.org/web/20130922015103/http://rogchap.com/2011/09/06/top-40-website-programming-languages/ |archivedate= September 22, 2013 }}</ref>

| content license = {{Nowrap|[[Creative Commons licenses|CC Attribution / Share-Alike]] 3.0}}<br />Most text is also dual-licensed under [[GFDL]]; media licensing varies


'''Wikipedia''' ({{IPAc-en|audio=En-uk-Wikipedia.ogg|ˌ|w|ɪ|k|ᵻ|ˈ|p|iː|d|i|ə}}, {{IPAc-en|audio=en-us-Wikipedia.ogg|ˌ|w|ɪ|k|i|ˈ|p|iː|d|i|ə}} {{respell|WIK|kee|PEE|dee|ə}}) is a multilingual [[online encyclopedia]], based on [[open collaboration]] through a [[wiki]]-based content editing system. It is the largest and most popular general reference work on the [[World Wide Web]],<ref name="Tancer" /><ref name="Woodson" /><ref>{{cite web |url = http://www.comscore.com/Insights/Press_Releases/2012/9/comScore_Media_Metrix_Ranks_Top_50_US_Web_Properties_for_August_201 |title= comScore MMX Ranks Top 50 US Web Properties for August 2012 |website= comScore |date= September 12, 2012 |accessdate= February 6, 2013 }}</ref> and is one of the most popular websites ranked by [[Alexa Internet|Alexa]] as of June 2019.<ref name="Alexa siteinfo" /> It features exclusively [[free content]] and no commercial [[Advertising|ads]], and is owned and supported by the [[Wikimedia Foundation]], a [[501(c)(3) organization|non-profit organization]] funded primarily through [[Donation|donations]].<ref>{{cite news |last1=Dewey |first1=Caitlin |title=Wikipedia has a ton of money. So why is it begging you to donate yours? |url=https://www.washingtonpost.com/news/the-intersect/wp/2015/12/02/wikipedia-has-a-ton-of-money-so-why-is-it-begging-you-to-donate-yours/ |access-date=April 10, 2019 |agency=''The Washington Post'' |date=December 2, 2015}}</ref><ref>{{cite news |title = Wikimedia pornography row deepens as Wales cedes rights – BBC News |url = https://www.bbc.com/news/10104946 |date= May 10, 2010 |access-date= June 28, 2016 |work= BBC }}</ref><ref>{{cite news |author= Vogel, Peter S. |title= The Mysterious Workings of Wikis: Who Owns What? |url = http://www.ecommercetimes.com/story/76351.html |date= October 10, 2012 |accessdate= June 28, 2016 |work= Ecommerce Times }}</ref><ref>{{cite news |title = Wikimedia Foundation employee ousted over paid editing |author= Mullin, Joe |url = https://arstechnica.com/tech-policy/2014/01/wikimedia-foundation-employee-ousted-over-paid-editing/ |date= January 10, 2014 |access-date= June 28, 2016 |work= Ars Technica }}</ref>

Wikipedia was launched on January 15, 2001, by [[Jimmy Wales]] and [[Larry Sanger]].<ref>{{Cite news|url=https://www.washingtonpost.com/lifestyle/magazine/wikipedia-was-born-in-2001-and-the-world-got-a-bit-truthier/2017/01/04/1d082742-bb0f-11e6-ac85-094a21c44abc_story.html|title=Wikipedia was born in 2001. And the world got a bit truthier.|last=Shin|first=Annys|date=January 5, 2017|work=The Washington Post|access-date=March 22, 2019}}</ref> Sanger coined its name,<ref name="MiliardWho"/><ref name="J Sidener"/> as a [[portmanteau]] of ''wiki'' (the [[Hawai'ian language|Hawai'ian]] [[Wikt:wiki#Hawaiian|word for "quick"]]<ref>{{cite news |title= Wiki |work= Hawaiian Dictionary |edition= Revised and enlarged |publisher= University of Hawaii Press |date = 1986 }}</ref>) and "encyclo''pedia''". Initially an English-language encyclopedia, versions in other languages were quickly developed. With [[Special:Statistics|{{NUMBEROFARTICLES}} articles]],{{refn|group=note|As of {{Currentdate}}.}} the [[English Wikipedia]] is the largest of the more than 290 Wikipedia encyclopedias.<!-- It was 292 as of 2015, but won't have to be updated as often if it's more vague --> Overall, Wikipedia comprises more than 40 million articles in 301 different languages<ref name="CBS">{{cite news |url = http://www.cbsnews.com/news/wikipedia-jimmy-wales-morley-safer-60-minutes/ |title= Wikipedia cofounder Jimmy Wales on 60 Minutes |accessdate= April 6, 2015 |work= [[CBS News]] }}</ref> and by February 2014 it had reached 18 billion page views and nearly 500 million unique visitors per month.<ref name="small screen"/>

In 2005, ''[[Nature (journal)|Nature]]'' published a peer review comparing 42 [[hard science]] articles from ''[[Encyclopædia Britannica]]'' and Wikipedia and found that Wikipedia's level of accuracy approached that of ''Britannica'',<ref name="GilesJ2005Internet"/> although critics suggested that it might not have fared so well in a similar study of a [[random sampling]] of all articles or one focused on social science or contentious social issues.<ref name="Reagle, pp. 165–166">Reagle, pp. 165–166.</ref><ref name="Orlowski2005">{{cite news |last1=Orlowski |first1=Andrew |title=Wikipedia science 31% more cronky than Britannica's Excellent for Klingon science, though |url=https://www.theregister.co.uk/2005/12/16/wikipedia_britannica_science_comparison/ |access-date=February 25, 2019 |work=[[The Register]] |date=December 16, 2005}}</ref> The following year, ''[[Time (magazine)|Time]]'' magazine stated that the open-door policy of allowing anyone to edit had made Wikipedia the biggest and possibly the best encyclopedia in the world, and was a testament to the vision of Jimmy Wales.<ref>{{Cite journal |url = http://content.time.com/time/specials/packages/article/0,28804,1975813_1975844_1976488,00.html |title= The 2006 Time 100 |journal= Time |date= May 8, 2006 |access-date= November 11, 2017 }}</ref>

Wikipedia [[Criticism of Wikipedia|has been criticized]] for exhibiting [[systemic bias]], for presenting a mixture of "truths, half truths, and some falsehoods",<ref name=EdwinBlack/> and for being subject to manipulation and [[spin (propaganda)|spin]] in controversial topics.<ref name=Petrilli/> However, [[Facebook]] announced that by 2017 it would help readers detect [[fake news]] by suggesting links to related Wikipedia articles. [[YouTube]] announced a similar plan in 2018.<ref name="auto">{{cite news|first=Noam|last=Cohen|title=Conspiracy videos? Fake news? Enter Wikipedia, the ‘good cop’ of the Internet|url=https://www.washingtonpost.com/outlook/conspiracy-videos-fake-news-enter-wikipedia-the-good-cop-of-the-internet/2018/04/06/ad1f018a-3835-11e8-8fd2-49fe3c675a89_story.html|work=The Washington Post|date=April 7, 2018|archive-url=https://web.archive.org/web/20180614045810/https://www.washingtonpost.com/outlook/conspiracy-videos-fake-news-enter-wikipedia-the-good-cop-of-the-internet/2018/04/06/ad1f018a-3835-11e8-8fd2-49fe3c675a89_story.html |archive-date=June 14, 2018 }}</ref>

{{TOC limit|3}}

== History ==

{{Main|History of Wikipedia}}

{{multiple image

| footer = Jimmy Wales and Larry Sanger

| width  =

| image1 = Jimmy Wales September 2015.jpg

| width1 = 100

| image2 = L Sanger.jpg

| width2 = 116


=== Nupedia ===


[[File:Nupedia logo and wordmark.png|thumb|alt=Logo reading "Nupedia.com the free encyclopedia" in blue with large initial "N"|Wikipedia originally developed from another encyclopedia project called Nupedia]]

Other collaborative online encyclopedias were attempted before Wikipedia, but none were as successful.<ref>{{cite web |url = http://www.niemanlab.org/2011/10/the-contribution-conundrum-why-did-wikipedia-succeed-while-other-encyclopedias-failed/ |title = The contribution conundrum: Why did Wikipedia succeed while other encyclopedias failed? |website = Nieman Lab |accessdate = June 5, 2016 }}</ref> Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process.<ref name="KockJungSyn2016">Kock, N., Jung, Y., & Syn, T. (2016). [http://cits.tamiu.edu/kock/pubs/journals/2016JournalIJeC_WikipediaEcollaboration/Kock_etal_2016_IJeC_WikipediaEcollaboration.pdf Wikipedia and e-Collaboration Research: Opportunities and Challenges.] (PDF) {{webarchive |url=https://web.archive.org/web/20160927001627/http://cits.tamiu.edu/kock/pubs/journals/2016JournalIJeC_WikipediaEcollaboration/Kock_etal_2016_IJeC_WikipediaEcollaboration.pdf |date=September 27, 2016 }} ''International Journal of e-Collaboration'' (IJeC), 12(2), 1–8.</ref> It was founded on March 9, 2000, under the ownership of [[Bomis]], a [[web portal]] company. Its main figures were Bomis CEO [[Jimmy Wales]] and [[Larry Sanger]], editor-in-chief for Nupedia and later Wikipedia.<ref name="autogenerated1"/><ref name="Meyers"/> Nupedia was initially licensed under its own Nupedia [[Open Content]] License, but even before Wikipedia was founded, Nupedia switched to the [[GNU Free Documentation License]] at the urging of [[Richard Stallman]].<ref name="stallman1999"/> Wales is credited with defining the goal of making a publicly editable encyclopedia,<ref name="SangerMemoir" /><ref name="Sanger"/> while Sanger is credited with the strategy of using a [[wiki]] to reach that goal.<ref name="WM foundation of WP 1">{{cite web |url = http://lists.wikimedia.org/pipermail/wikipedia-l/2001-October/000671.html |title = Wikipedia-l: LinkBacks? |accessdate = February 20, 2007 }}</ref> On January 10, 2001, Sanger proposed on the Nupedia mailing list to create a wiki as a "feeder" project for Nupedia.<ref name="nupedia feeder from WP 1">{{cite news |first = Larry |last = Sanger |title = Let's Make a Wiki |date = January 10, 2001 |publisher = Internet Archive |url = http://www.nupedia.com/pipermail/nupedia-l/2001-January/000676.html |archiveurl = https://web.archive.org/web/20030414014355/http://www.nupedia.com/pipermail/nupedia-l/2001-January/000676.html |archivedate = April 14, 2003 |accessdate = December 26, 2008 }}</ref>

{{external media | width = 230px | align = right | audio1 = [http://www.cbc.ca/ideas/episodes/2014/01/15/the-great-book-of-knowledge-part-1/ The Great Book of Knowledge, Part 1], ''Ideas with [[Paul Kennedy (host)|Paul Kennedy]]'', [[Canadian Broadcasting Corporation|CBC]], January 15, 2014


=== Launch and early growth ===

The [[Domain name|domains]] ''wikipedia.com'' and ''wikipedia.org'' were registered on January 12, 2001<ref>{{Cite web|url=http://www.networksolutions.com/whois/results.jsp?domain=wikipedia.com|archive-url=https://web.archive.org/web/20070927193149/http://www.networksolutions.com/whois/results.jsp?domain=wikipedia.com|dead-url=yes|archive-date=September 27, 2007|title=WHOIS domain registration information results for wikipedia.com from Network Solutions|date=September 27, 2007|access-date=August 31, 2018}}</ref> and January 13, 2001<ref>{{Cite web|url=http://www.networksolutions.com/whois/results.jsp?domain=wikipedia.org|archive-url=https://web.archive.org/web/20070927194913/http://www.networksolutions.com/whois/results.jsp?domain=wikipedia.org|dead-url=yes|archive-date=September 27, 2007|title=WHOIS domain registration information results for wikipedia.org from Network Solutions|date=September 27, 2007|access-date=August 31, 2018}}</ref> respectively, and Wikipedia was launched on January 15, 2001,<ref name="KockJungSyn2016" /> as a single English-language edition at www.wikipedia.com,<ref name="WikipediaHome" /> and announced by Sanger on the Nupedia mailing list.<ref name="SangerMemoir" /> Wikipedia's policy of "neutral point-of-view"<ref name="NPOV" /> was codified in its first few months. Otherwise, there were relatively few rules initially and Wikipedia operated independently of Nupedia.<ref name="SangerMemoir" /> Originally, Bomis intended to make Wikipedia a business for profit.<ref name="Seth-Finkelstein">{{cite news |url = https://www.theguardian.com/technology/2008/sep/25/wikipedia.internet |title = Read me first: Wikipedia isn't about human potential, whatever Wales says |author = Finkelstein, Seth |work = [[The Guardian]] |date = September 25, 2008 |location = London }}</ref>

Wikipedia gained early contributors from Nupedia, [[Slashdot]] postings, and [[web search engine]] indexing. Language editions were also created, with a total of 161 by the end of 2004.<ref name="WP early language stats 1">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Multilingual_statistics |title = Multilingual statistics |website = Wikipedia |date = March 30, 2005 |accessdate = December 26, 2008 }}</ref> Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, and its text was incorporated into Wikipedia. The English Wikipedia passed the mark of two million articles on September 9, 2007, making it the largest encyclopedia ever assembled, surpassing the 1408 ''[[Yongle Encyclopedia]]'', which had held the record for almost 600&nbsp;years.<ref name="EB_encyclopedia" />

Citing fears of [[commercial advertising]] and lack of control in [[List of Wikipedias|Wikipedia]], users of the [[Spanish Wikipedia]] [[Fork (software development)|forked]] from Wikipedia to create the [[Enciclopedia Libre Universal en Español|Enciclopedia Libre]] in February 2002.<ref name="EL fears and start 1">{{cite web |title = [long] Enciclopedia Libre: msg#00008 |url = http://osdir.com/ml/science.linguistics.wikipedia.international/2003-03/msg00008.html |website = Osdir |accessdate = December 26, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20081006065927/http://osdir.com/ml/science.linguistics.wikipedia.international/2003-03/msg00008.html |archivedate = October 6, 2008 |df = mdy-all }}</ref> These moves encouraged Wales to announce that Wikipedia would not display advertisements, and to change Wikipedia's domain from ''wikipedia.com'' to ''wikipedia.org''.<ref name="Shirky" />

Though the English Wikipedia reached three million articles in August 2009, the growth of the edition, in terms of the numbers of new articles and of contributors, appears to have peaked around early 2007.<ref name="guardian WP user peak 1">{{cite news |url = https://www.theguardian.com/technology/2009/aug/12/wikipedia-deletionist-inclusionist |title = Wikipedia approaches its limits |author = Bobbie Johnson |work = The Guardian |location = London |date = August 12, 2009 |accessdate = March 31, 2010 }}</ref> Around 1,800 articles were added daily to the encyclopedia in 2006; by 2013 that average was roughly 800.<ref name="WP growth modelling 1">{{srlink|Wikipedia:Modelling_Wikipedia_extended_growth}}</ref> A team at the [[Palo Alto Research Center]] attributed this slowing of growth to the project's increasing exclusivity and resistance to change.<ref name="wikisym slowing growth 1">{{cite conference |url = http://www.wikisym.org/ws2009/procfiles/p108-suh.pdf |title = The Singularity is Not Near: Slowing Growth of Wikipedia |year = 2009 |location = Orlando, Florida |conference = The International Symposium on Wikis |deadurl = yes |archiveurl = https://web.archive.org/web/20110511110022/http://www.wikisym.org/ws2009/procfiles/p108-suh.pdf |archivedate = May 11, 2011 }}</ref><!-- ''Hidden whilst in discussion on the talk page'': New or occasional editors have significantly higher rates of their edits reverted (removed) than an elite group of regular editors, colloquially known as "the [[cabal]]". This could make it more difficult for the project to recruit and retain new contributors over the long term, resulting in stagnation in article creation. --> Others suggest that the growth is flattening naturally because articles that could be called "[[wikt:low-hanging fruit|low-hanging fruit]]"—topics that clearly merit an article—have already been created and built up extensively.<ref name="bostonreview the end of WP 1">{{cite news |url = http://www.bostonreview.net/books-ideas/edit-page-wikipedia-evgeny-morozov |title = Edit This Page; Is it the end of Wikipedia |publisher = ''Boston Review'' |author = Evgeny Morozov |date = November–December 2009 }}</ref><ref>{{cite news |last = Cohen |first = Noam |url = https://www.nytimes.com/2009/03/29/weekinreview/29cohen.html |title = Wikipedia – Exploring Fact City |work = The New York Times |date = March 28, 2009 |accessdate = April 19, 2011 }}</ref><ref name="stanford WP lack of future growth 1">Austin Gibbons, David Vetrano, Susan Biancani (2012). [http://snap.stanford.edu/class/cs341-2012/reports/09-GibbonsVetranoBiancaniCS341.pdf Wikipedia: Nowhere to grow] {{Webarchive|url=https://web.archive.org/web/20140718091331/http://snap.stanford.edu/class/cs341-2012/reports/09-GibbonsVetranoBiancaniCS341.pdf |date=July 18, 2014 }} {{open access}}</ref>

{{anchor|Decline in participation since 2009}}

In November 2009, a researcher at the [[Rey Juan Carlos University]] in [[Madrid]] found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; in comparison, the project lost only 4,900 editors during the same period in 2008.<ref name="guardian editors leaving 1">{{cite news |url = https://www.theguardian.com/technology/2009/nov/26/wikipedia-losing-disgruntled-editors |title = Wikipedia falling victim to a war of words |work = The Guardian |location = London |author = Jenny Kleeman |date = November 26, 2009 |accessdate = March 31, 2010 }}</ref><ref>{{cite journal |url = http://libresoft.es/publications/thesis-jfelipe |title = Wikipedia: A quantitative analysis |format = PDF |archiveurl = https://web.archive.org/web/20120403172516/http://libresoft.es/publications/thesis-jfelipe |archivedate = April 3, 2012 }}</ref> ''The Wall Street Journal'' cited the array of rules applied to editing and disputes related to such content among the reasons for this trend.<ref name="WSJ WP losing editors 1">Volunteers Log Off as Wikipedia Ages, The Wall Street Journal, November 27, 2009.</ref> Wales disputed these claims in 2009, denying the decline and questioning the methodology of the study.<ref name="telegraph Wales WP not losing editors 1">{{cite news |url = https://www.telegraph.co.uk/technology/wikipedia/6660646/Wikipedias-Jimmy-Wales-denies-site-is-losing-thousands-of-volunteer-editors.html |title = Wikipedia's Jimmy Wales denies site is 'losing' thousands of volunteer editors |first = Emma |last = Barnett |work = The Daily Telegraph |location = London |date = November 26, 2009 |accessdate = March 31, 2010 }}</ref> Two years later, in 2011, Wales acknowledged the presence of a slight decline, noting a decrease from "a little more than 36,000 writers" in June 2010 to 35,800 in June 2011. In the same interview, Wales also claimed the number of editors was "stable and sustainable".<ref name="wiki-women" /> A 2013 article titled "The Decline of Wikipedia" in MIT's ''[[Technology Review]]'' questioned this claim. The article revealed that since 2007, Wikipedia had lost a third of its volunteer editors, and those still there have focused increasingly on minutiae.<ref name="Simonite-2013">{{cite journal |last = Simonite |first = Tom |url = http://www.technologyreview.com/featuredstory/520446/the-decline-of-wikipedia/ |title = The Decline of Wikipedia |date = October 22, 2013 |journal = [[MIT Technology Review]] |accessdate = November 30, 2013 }}</ref> In July 2012, ''[[The Atlantic]]'' reported that the number of administrators is also in decline.<ref>{{cite news |url = https://www.theatlantic.com/technology/archive/2012/07/3-charts-that-show-how-wikipedia-is-running-out-of-admins/259829 |title = 3 Charts That Show How Wikipedia Is Running Out of Admins |work = The Atlantic |date = July 16, 2012 }}</ref> In the November 25, 2013, issue of ''[[New York (magazine)|New York]]'' magazine, Katherine Ward stated "Wikipedia, the sixth-most-used website, is facing an internal crisis".<ref>Ward, Katherine. ''New York'' Magazine, issue of November 25, 2013, p. 18.</ref>


[[File:History Wikipedia English SOPA 2012 Blackout2.jpg|thumb|right|Wikipedia blackout protest against [[Stop Online Piracy Act|SOPA]] on January 18, 2012]]

[[File:Wikipedia Edit 2014.webm|thumb|right|A promotional video of the Wikimedia Foundation that encourages viewers to edit Wikipedia, mostly reviewing 2014 via Wikipedia content]]<!-- Appropriateness debated in Talk:Wikipedia#Promotional video -->

=== Milestones ===

In January 2007, Wikipedia entered for the first time the top-ten [[List of most popular websites|list of the most popular websites]] in the US, according to [[comScore]] Networks. With 42.9 million unique visitors, Wikipedia was ranked number 9, surpassing ''[[The New York Times]]'' (#10) and [[Apple Inc.|Apple]] (#11). This marked a significant increase over January 2006, when the rank was number 33, with Wikipedia receiving around 18.3 million unique visitors.<ref>{{cite web |url = http://www.pcworld.com/article/129135/wikipedia_breaks_into_us_top_10_sites.html |title = Wikipedia Breaks Into US Top 10 Sites |publisher = PCWorld |date = February 17, 2007 }}</ref> {{as of|2019|05}}, Wikipedia has rank 5<ref name="Alexa siteinfo" /><ref name="Alexa top">{{cite web |url = http://www.alexa.com/siteinfo/wikipedia.org |title = Wikipedia.org Site Overview |website = alexa.com |accessdate = May 2, 2019 }}</ref> among websites in terms of popularity according to [[Alexa Internet]]. In 2014, it received 8 billion pageviews every month.<ref>{{cite web |url = http://stats.wikimedia.org/wikimedia/squids/SquidReportPageViewsPerCountryOverview.htm |title = Wikimedia Traffic Analysis Report – Wikipedia Page Views Per Country |publisher = Wikimedia Foundation |accessdate = March 8, 2015 }}</ref> On February 9, 2014, ''The New York Times'' reported that Wikipedia has 18 billion [[page view]]s and nearly 500 million [[unique visitor]]s a month, "according to the ratings firm comScore."<ref name="small screen">{{cite news |url = https://www.nytimes.com/2014/02/10/technology/wikipedia-vs-the-small-screen.html?_r=0 |title = Wikipedia vs. the Small Screen |work = The New York Times |date = February 9, 2014 |last = Cohen |first = Noam }}</ref>

On January 18, 2012, the English Wikipedia participated in a series of coordinated protests against two proposed laws in the [[United States Congress]]—the [[Stop Online Piracy Act]] (SOPA) and the [[PROTECT IP Act]] (PIPA)—by [[2012 Wikipedia blackout|blacking out its pages for 24 hours]].<ref name="LA Times Jan 19">{{cite news |url = http://latimesblogs.latimes.com/technology/2012/01/wikipedia-sopa-blackout-congressional-representatives.html |title = Wikipedia: SOPA protest led 8 million to look up reps in Congress |first = Deborah |last = Netburn |work = Los Angeles Times |date = January 19, 2012 |accessdate = March 6, 2012 }}</ref> More than 162 million people viewed the blackout explanation page that temporarily replaced Wikipedia content.<ref name="BBC WP blackout protest 1">{{cite news |title = Wikipedia joins blackout protest at US anti-piracy moves |url = https://www.bbc.co.uk/news/technology-16590585 |publisher = BBC News |date = January 18, 2012 |accessdate = January 19, 2012 }}</ref><ref>{{cite web |url = https://wikimediafoundation.org/wiki/SOPA/Blackoutpage |title = SOPA/Blackoutpage |publisher = Wikimedia Foundation |accessdate = January 19, 2012 |archiveurl=https://web.archive.org/web/20180622185443/https://wikimediafoundation.org/wiki/SOPA/Blackoutpage |archivedate = June 22, 2018 |deadurl=yes}}</ref>

[[File:Wikipedia-2001.jpg|thumb|The Wikipedia Page on December 17, 2001]]

Loveland and Reagle argue that, in process, Wikipedia follows a long tradition of historical encyclopedias that accumulated improvements piecemeal through "[[Stigmergy|stigmergic]] accumulation".<ref name="sagepub WP and encyclopedic production 1">{{cite journal |url = http://nms.sagepub.com/content/early/2013/01/13/1461444812470428.full |title = Wikipedia and encyclopedic production. New Media & Society. Sage Journals |author = Jeff Loveland and Joseph Reagle |date = January 15, 2013 |journal = New Media & Society |doi = 10.1177/1461444812470428 |volume = 15 |issue = 8 |page = 1294 }}</ref><ref name="theatlantic WP actually a reversion 1">{{cite web |url = https://www.theatlantic.com/technology/archive/2013/01/what-if-the-great-wikipedia-revolution-was-actually-a-reversion/272697 |title = What If the Great Wikipedia 'Revolution' Was Actually a Reversion? • The Atlantic |author = Rebecca J. Rosen |date = January 30, 2013 |accessdate = February 9, 2013 }}</ref>

On January 20, 2014, Subodh Varma reporting for ''[[The Economic Times]]'' indicated that not only had Wikipedia's growth stalled, but that it "had lost nearly 10 per cent of its page views last year. There was a decline of about 2 billion between December 2012 and December 2013. Its most popular versions are leading the slide: page-views of the English Wikipedia declined by 12 per cent, those of German version slid by 17 per cent and the Japanese version lost 9 per cent."<ref name="economictimes.indiatimes.com">{{cite news |first = Subodh |last = Varma |title = Google eating into Wikipedia page views? |date = January 20, 2014 |publisher = [[Times Internet Limited]] |url = http://economictimes.indiatimes.com/articleshow/29094246.cms |work = The Economic Times |accessdate = February 10, 2014 }}</ref> Varma added that, "While Wikipedia's managers think that this could be due to errors in counting, other experts feel that Google's [[Knowledge Graph]]s project launched last year may be gobbling up Wikipedia users."<ref name="economictimes.indiatimes.com" /> When contacted on this matter, [[Clay Shirky]], associate professor at New York University and fellow at Harvard's Berkman Center for Internet and Security indicated that he suspected much of the page view decline was due to Knowledge Graphs, stating, "If you can get your question answered from the search page, you don't need to click [any further]."<ref name="economictimes.indiatimes.com" />

By the end of December 2016, Wikipedia was ranked fifth in the most popular websites globally.<ref name="Alexa">{{cite web |url = http://www.alexa.com/topsites |title = Alexa Top 500 Global Sites |website = [[Alexa Internet]] |accessdate = December 28, 2016 }}</ref>

== Openness ==

{{Wikipedia article graph|caption=Number of English Wikipedia articles}}{{Wikipedia editor graph}}

[[File:History Comparison Example (Vector).png|thumb|Differences between versions of an article are highlighted as shown]]

Unlike traditional encyclopedias, Wikipedia follows the [[procrastination]] principle<ref group=note>The procrastination principle dictates that you should wait for problems to arise before solving them.</ref><ref name=zittrain /> regarding the security of its content.<ref name=zittrain>{{cite book |last = Zittrain |first = Jonathan |title = The Future of the Internet and How to Stop It&nbsp;– Chapter 6: The Lessons of Wikipedia |author-link = Jonathan Zittrain |publisher = Yale University Press |year = 2008 |url = http://yupnet.org/zittrain/archives/16 |isbn = 978-0-300-12487-3 |accessdate = December 26, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20090216015857/http://yupnet.org/zittrain/archives/16 |archivedate = February 16, 2009 }}</ref> It started almost entirely open—anyone could create articles, and any Wikipedia article could be edited by any reader, even those who did not have a Wikipedia account. Modifications to all articles would be published immediately. As a result, any article could contain inaccuracies such as errors, [[ideological bias on Wikipedia|ideological biases]], and nonsensical or irrelevant text.

=== Restrictions ===

Due to the increasing popularity of Wikipedia, some editions, including the English version, have introduced editing restrictions in some cases. For instance, on the English Wikipedia and some other language editions, only registered users may create a new article.<ref>{{srlink|Wikipedia:Tutorial/Registration|Registration notes}}</ref> On the English Wikipedia, among others, some particularly controversial, sensitive and/or vandalism-prone pages have been protected to some degree.<ref name="WP protection policy 1">{{srlink|Wikipedia:Protection policy|Protection Policy}}</ref><ref>{{cite news |last1 = Hafner |first1 = Katie |title = Growing Wikipedia Refines Its 'Anyone Can Edit' Policy |url = https://www.nytimes.com/2006/06/17/technology/17wiki.html |accessdate = December 5, 2016 |work = The New York Times |date = June 17, 2006 }}</ref> A frequently vandalized article can be [[Help:Semi-protection|semi-protected]] or [[WP:ECP|extended confirmed protected]], meaning that only [[Wikipedia:Autoconfirmed|autoconfirmed]] or [[WP:XCON|extended confirmed]] editors are able to modify it.<ref>[[Wikipedia:Protection policy|English Wikipedia's protection policy]]</ref> A particularly contentious article may be locked so that only [[Administrators (Wikipedia)|administrators]] are able to make changes.<ref>{{srlink|Wikipedia:Full protection|English Wikipedia's full protection policy}}</ref>

In certain cases, all editors are allowed to submit modifications, but review is required for some editors, depending on certain conditions. For example, the [[German Wikipedia]] maintains "stable versions" of articles,<ref name="WP some sites stable versions 1">{{cite mailing list |first = P. |last = Birken |url = http://lists.wikimedia.org/pipermail/wikide-l/2008-December/021594.html |title = Bericht Gesichtete Versionen |mailinglist = Wikide-l |date = December 14, 2008 |language = German |publisher = Wikimedia Foundation |accessdate = February 15, 2009 }}</ref> which have passed certain reviews. Following protracted trials and community discussion, the English Wikipedia introduced the "pending changes" system in December 2012.<ref name="BInsider pending changes intro 1">{{cite news |url = http://www.businessinsider.com/pending-changes-safeguard-on-wikipedia-2012-12 |title = Wikipedia Has Figured Out A New Way To Stop Vandals In Their Tracks |work = Business Insider |author = William Henderson |date = December 10, 2012 }}</ref> Under this system, new and unregistered users' edits to certain controversial or vandalism-prone articles are reviewed by established users before they are published.<ref>{{Cite newspaper |last = Frewin |first = Jonathan |url = https://www.bbc.com/news/10312095 |title = Wikipedia unlocks divisive pages for editing |journal = BBC News |date = June 15, 2010 |accessdate = August 21, 2014 }}</ref>

[[File:Wikipedia editing interface.png|thumb|left|The editing interface of Wikipedia]]

=== Review of changes ===

Although changes are not systematically reviewed, the software that powers Wikipedia provides certain tools allowing anyone to review changes made by others. The "History" page of each article links to each revision.<ref group=note>Revisions with libelous content, criminal threats, or copyright infringements [[WP:Suppression|may be removed completely]].</ref><ref name="Torsten_Kleinz" /> On most articles, anyone can undo others' changes by clicking a link on the article's history page. Anyone can view the [[Help:Recent changes|latest changes]] to articles, and anyone may maintain a [[Recent changes|"watchlist"]] of articles that interest them so they can be notified of any changes. "New pages patrol" is a process whereby newly created articles are checked for obvious problems.<ref>[[Wikipedia:New pages patrol]]</ref>

In 2003, economics PhD student Andrea Ciffolilli argued that the low [[transaction cost]]s of participating in a [[wiki]] create a catalyst for collaborative development, and that features such as allowing easy access to past versions of a page favor "creative construction" over "creative destruction".<ref name="FMonday collaborative effort 1">Andrea Ciffolilli, [http://firstmonday.org/article/view/1108/1028 "Phantom authority, self-selective recruitment and retention of members in virtual communities: The case of Wikipedia"] {{webarchive |url=https://web.archive.org/web/20161206104747/http://firstmonday.org/article/view/1108/1028 |date=December 6, 2016 }}, ''[[First Monday (journal)|First Monday]]'' December 2003.</ref>

=== Vandalism ===

{{Main|Vandalism on Wikipedia}}

Any change or edit that manipulates content in a way that purposefully compromises the integrity of Wikipedia is considered vandalism. The most common and obvious types of vandalism include additions of obscenities and crude humor. Vandalism can also include advertising and other types of spam.<ref name="upenn link spamming 1">{{cite conference |last1 = West |first1 = Andrew G. |last2 = Chang |first2 = Jian |last3 = Venkatasubramanian |first3 = Krishna |last4 = Sokolsky |first4 = Oleg |last5 = Lee |first5 = Insup |title = Link Spamming Wikipedia for Profit |conference = 8th Annual Collaboration, Electronic Messaging, Anti-Abuse, and Spam Conference |pages = 152–161 |date = 2011 |url = http://repository.upenn.edu/cgi/viewcontent.cgi?article=1508&context=cis_papers |doi = 10.1145/2030376.2030394 }}</ref> Sometimes editors commit vandalism by removing content or entirely blanking a given page. Less common types of vandalism, such as the deliberate addition of plausible but false information to an article can be more difficult to detect. Vandals can introduce irrelevant formatting, modify page semantics such as the page's title or categorization, manipulate the underlying code of an article, or use images disruptively.<ref name="WP vandalism manipulation 1" />

[[File:John Seigenthaler Sr. speaking.jpg|thumb|alt=White-haired elderly gentleman in suit and tie speaks at a podium.|American journalist [[John Seigenthaler]] (1927–2014), subject of the [[Seigenthaler incident]]]]

Obvious vandalism is generally easy to remove from Wikipedia articles; the median time to detect and fix vandalism is a few minutes.<ref name="MIT_IBM_study" /><ref name="CreatingDestroyingAndRestoringValue" /> However, some vandalism takes much longer to repair.<ref name="Seigenthaler" />

In the [[Seigenthaler biography incident]], an anonymous editor introduced false information into the biography of American political figure [[John Seigenthaler]] in May 2005. Seigenthaler was falsely presented as a suspect in the assassination of John F. Kennedy.<ref name="Seigenthaler" /> The article remained uncorrected for four months.<ref name="Seigenthaler" /> Seigenthaler, the founding editorial director of ''[[USA Today]]'' and founder of the [[Freedom Forum]] [[First Amendment Center]] at [[Vanderbilt University]], called Wikipedia co-founder Jimmy Wales and asked whether he had any way of knowing who contributed the misinformation. Wales replied that he did not, although the perpetrator was eventually traced.<ref name="book The World is Flat 1">{{cite book |last = Friedman |first = Thomas L. |title = The World is Flat |year = 2007 |publisher = [[Farrar, Straus & Giroux]] |isbn = 978-0-374-29278-2 |page = 124 }}</ref><ref>{{cite web |url = http://archive.firstamendmentcenter.org/news.aspx?id=17798 |title = Founder shares cautionary tale of libel in cyberspace |last = Buchanan |first = Brian |date = November 17, 2006 |publisher = archive.firstamendmentcenter.org |archive-url = https://web.archive.org/web/20121221140311/http://archive.firstamendmentcenter.org/news.aspx?id=17798 |archive-date = December 21, 2012 |dead-url = yes |access-date = November 17, 2012 }}</ref> After the incident, Seigenthaler described Wikipedia as "a flawed and irresponsible research tool".<ref name="Seigenthaler" /> This incident led to policy changes at Wikipedia, specifically targeted at tightening up the verifiability of {{srlink|Wikipedia:Biographies of living persons|biographical articles of living people}}.<ref>{{cite news |last = Helm |first = Burt |title = Wikipedia: "A Work in Progress" |url = http://www.businessweek.com/stories/2005-12-13/wikipedia-a-work-in-progress |newspaper = [[BusinessWeek]] |date = December 13, 2005 |accessdate = July 26, 2012 |deadurl = yes |archiveurl = https://web.archive.org/web/20120708062333/http://www.businessweek.com/stories/2005-12-13/wikipedia-a-work-in-progress |archivedate = July 8, 2012 }}</ref>

<span id="Rules_and_laws_governing_content">Policies and laws</span>{{anchor|Rules and laws governing content and editor behavior}}[edit | edit source]


{{external media | width = 220px | float = right |headerimage=[[File:Jimbo at Fosdem cropped.jpg|210px]] | video1 =

[http://www.cbsnews.com/news/wikipedia-jimmy-wales-morley-safer-60-minutes/ Wikimania], ''[[60 Minutes]]'', [[CBS]], 20 minutes, April 5, 2015, co-founder Jimmy Wales at [[Fosdem]] | accessdate =April 5, 2015 }}

Content in Wikipedia is subject to the laws (in particular, [[copyright]] laws) of the United States and of the US state of [[Virginia]], where the majority of Wikipedia's servers are located. Beyond legal matters, the editorial principles of Wikipedia are embodied in the {{srlink|WP:Five pillars|"five pillars"}} and in numerous {{srlink|Wikipedia:List of policies and guidelines|policies and guidelines}} intended to appropriately shape content. Even these rules are stored in wiki form, and Wikipedia editors write and revise the website's policies and guidelines.<ref name="pcworld who's behind WP">{{cite web |url = http://www.pcworld.idg.com.au/index.php/id;1866322157;fp;2;fpid;2 |title = Who's behind Wikipedia? |website = PC World |date = February 6, 2008 |accessdate = February 7, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20080209110303/http://www.pcworld.idg.com.au/index.php/id%3B1866322157%3Bfp%3B2%3Bfpid%3B2 |archivedate = February 9, 2008 |df = }}</ref> Editors can {{srlink|Wikipedia:Enforcement|enforce these rules}} by deleting or modifying non-compliant material. Originally, rules on the non-English editions of Wikipedia were based on a translation of the rules for the English Wikipedia. They have since diverged to some extent.<ref name="WP some sites stable versions 1" />

Content policies and guidelines{{anchor|Content policies}}[edit | edit source]

According to the rules on the English Wikipedia, each entry in Wikipedia must be about a topic that is [[wikt:encyclopedic|encyclopedic]] and is not a dictionary entry or dictionary-like.<ref name="WP content policy 1">{{srlink|Wikipedia:What Wikipedia is not|What Wikipedia is not}}. Retrieved April 1, 2010. "Wikipedia is not a dictionary, usage, or jargon guide."</ref> A topic should also meet [[Notability in the English Wikipedia|Wikipedia's standards of "notability"]],<ref name="WP notability guide 1">{{srlink|Wikipedia:Notability|Notability}}. Retrieved February 13, 2008. "A topic is presumed to be notable if it has received significant coverage in reliable secondary sources that are independent of the subject."</ref> which generally means that the topic must have been covered in mainstream media or major academic journal sources that are independent of the article's subject. Further, Wikipedia intends to convey only knowledge that is already established and recognized.<ref name="NOR" /> [[WP:No original research|It must not present original research]]. A claim that is likely to be challenged requires a reference to a [[WP:Identifying reliable sources|reliable source]]. Among Wikipedia editors, this is often phrased as "verifiability, not truth" to express the idea that the readers, not the encyclopedia, are ultimately responsible for checking the truthfulness of the articles and making their own interpretations.<ref name="WP Verifiability policy 1">{{srlink|Wikipedia:Verifiability|Verifiability}}. February 13, 2008. "Material challenged or likely to be challenged, and all quotations, must be attributed to a reliable, published source."</ref> This can at times lead to the removal of information that, though valid, is not properly sourced.<ref name="IHT WP valid info wrong removable 1">{{cite news |last = Cohen |first = Noam |title = For inclusive mission, Wikipedia is told that written word goes only so far |newspaper = [[International Herald Tribune]] |page = 18 |date = August 9, 2011 |df = }}{{paywall}}</ref> Finally, Wikipedia must not take sides.<ref name="autogenerated2" /> All opinions and viewpoints, if attributable to external sources, must enjoy an appropriate share of coverage within an article. This is known as neutral point of view (NPOV).

== Governance ==


Wikipedia's initial [[anarchy]] integrated [[democracy|democratic]] and hierarchical elements over time.<ref>{{cite web |last1 = Sanger |first1 = Larry |title = The Early History of Nupedia and Wikipedia: A Memoir |url = http://features.slashdot.org/story/05/04/18/164213/the-early-history-of-nupedia-and-wikipedia-a-memoir |website = Slashdot |publisher = Dice |date = April 18, 2005 }}</ref><ref>{{Cite journal |last1 = Kostakis |first1 = Vasilis |title = Identifying and understanding the problems of Wikipedia's peer governance: The case of inclusionists versus deletionists |issue = 3 |url = http://firstmonday.org/ojs/index.php/fm/article/view/2613/2479 |journal = First Monday |volume = 15 |date = March 2010 }}</ref> An article is not considered to be owned by its creator or any other editor, nor by the subject of the article.<ref>{{srlink|Wikipedia:Ownership of articles|Ownership of articles}}</ref>

=== Administrators ===

[[Wikipedia:Wikipedians|Editors]] in good standing in the community can run for one of many levels of volunteer stewardship: this begins with "[[Administrators (Wikipedia)|administrator]]",<ref>{{srlink|Wikipedia:Administrators}}</ref><ref name="David_Mehegan"/> privileged users who can delete pages, prevent articles from being changed in case of vandalism or editorial disputes (setting protective measures on articles), and try to prevent certain persons from editing. Despite the name, administrators are not supposed to enjoy any special privilege in decision-making; instead, their powers are mostly limited to making edits that have project-wide effects and thus are disallowed to ordinary editors, and to implement restrictions intended to prevent certain persons from making disruptive edits (such as vandalism).<ref>{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Administrators#Administrator_conduct |title = Wikipedia:Administrators |accessdate = July 12, 2009 |date = October 3, 2018 }}</ref><ref>{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:RfA_Review/Reflect |title = Wikipedia:RfA_Review/Reflect |accessdate = September 24, 2009 |date = January 22, 2017 }}</ref>

Fewer editors become administrators than in years past, in part because the process of vetting potential Wikipedia administrators has become more rigorous.<ref>{{cite web |url = https://www.theatlantic.com/technology/archive/2012/07/3-charts-that-show-how-wikipedia-is-running-out-of-admins/259829 |title = 3 Charts That Show How Wikipedia Is Running Out of Admins |last = Meyer |first = Robinson |website = [[The Atlantic]] |date = July 16, 2012 |accessdate = September 2, 2012 }}</ref>

[[Wikipedia:Bureaucrats|Bureaucrats]] name new administrators solely upon the recommendations from the community.

=== Dispute resolution ===

Wikipedians often have disputes regarding content, which may result in repeatedly making opposite changes to an article, known as [[WP:EW|"edit warring"]].<ref>{{srlink|Wikipedia:Dispute Resolution|Dispute Resolution}}</ref><ref name="NBC WP editorial warzone 1" /> Over time, Wikipedia has developed a semi-formal dispute resolution process to assist in such circumstances. In order to determine community consensus, editors can raise issues at appropriate community forums,<ref group=note>See for example the [[Wikipedia:Biographies of living persons/Noticeboard|Biographies of Living Persons Noticeboard]] or [[Wikipedia:Neutral point of view/Noticeboard|Neutral Point of View Noticeboard]], created to address content falling under their respective areas.</ref> or seek outside input through [[Wikipedia:Third opinion|third opinion requests]] or by initiating a more general community discussion known as a [[WP:RfC|"request for comment"]].

==== Arbitration Committee ====

{{Main|Arbitration Committee}}

The Arbitration Committee presides over the ultimate dispute resolution process. Although disputes usually arise from a disagreement between two opposing views on how an article should read, the Arbitration Committee explicitly refuses to directly rule on the specific view that should be adopted. Statistical analyses suggest that the committee ignores the content of disputes and rather focuses on the way disputes are conducted,<ref name="emory disputes handled 1" /> functioning not so much to resolve disputes and make peace between conflicting editors, but to weed out problematic editors while allowing potentially productive editors back in to participate. Therefore, the committee does not dictate the content of articles, although it sometimes condemns content changes when it deems the new content violates Wikipedia policies (for example, if the new content is considered [[Wikipedia:Neutral point of view|biased]]). Its remedies include cautions and [[WP:Probation|probations]] (used in 63% of cases) and [[WP:BAN|banning editors from articles]] (43%), subject matters (23%), or Wikipedia (16%). Complete bans from Wikipedia are generally limited to instances of impersonation and [[anti-social behavior]]. When conduct is not impersonation or anti-social, but rather anti-consensus or in violation of editing policies, remedies tend to be limited to warnings.<ref>{{cite journal |title = Wikitruth through Wikiorder |ssrn = 1354424 |journal = [[Emory Law Journal]] |volume = 59 |issue = 1 |year = 2009 |pages = 151–210 |author = David A. Hoffman |author2 = Salil K. Mehra }}</ref>

== Community ==

{{Main|Wikipedia community}}

[[File:Wikimania - the Wikimentary.webm|thumb|Video of [[Wikimania#2005|Wikimania 2005]] – an annual conference for users of Wikipedia and other projects operated by the [[Wikimedia Foundation]], was held in [[Frankfurt am Main]], [[Germany]] from August 4 to 8.]]

Each article and each user of Wikipedia has an associated "Talk" page. These form the primary communication channel for editors to discuss, coordinate and debate.<ref>{{cite journal |url = http://www.research.ibm.com/visual/papers/wikipedia_coordination_final.pdf |author = [[Fernanda B. Viégas]] |author2 = [[Martin M. Wattenberg]] |author3 = Jesse Kriss |author4 = Frank van Ham |title = Talk Before You Type: Coordination in Wikipedia |publisher = Visual Communication Lab, [[IBM Research]] |date = January 3, 2007 |accessdate = June 27, 2008 }}</ref>

[[File:Editing Hoxne Hoard at the British Museum.ogv|thumb|right|Wikipedians and [[British Museum]] curators collaborate on the article [[Hoxne Hoard]] in June 2010]]

Wikipedia's community has been described as [[cult]]-like,<ref>{{cite news |url = https://www.theguardian.com/technology/2005/dec/15/wikipedia.web20 |title = Log on and join in, but beware the web cults |first = Charles |last = Arthur |date = December 15, 2005 |work = [[The Guardian]] |location = London |accessdate = December 26, 2008 }}</ref> although not always with entirely negative connotations.<ref>{{cite news |url = http://www.cnn.com/2003/TECH/internet/08/03/wikipedia/index.html |title = Wikipedia: The know-it-all Web site |first = Kristie |last = Lu Stout |publisher = CNN |date = August 4, 2003 |accessdate = December 26, 2008 }}</ref> The project's preference for cohesiveness, even if it requires compromise that includes disregard of [[credential]]s, has been referred to as "[[anti-elitism]]".<ref>{{cite web |title = Why Wikipedia Must Jettison Its Anti-Elitism |url = http://www.kuro5hin.org/story/2004/12/30/142458/25 |website = [[Kuro5hin.org|Kuro5hin]], Op–Ed |author = [[Larry Sanger]] |date = December 31, 2004 |quote = There is a certain mindset associated with unmoderated Usenet groups [...] that infects the collectively-managed Wikipedia project: if you react strongly to trolling, that reflects poorly on you, not (necessarily) on the troll. If you [...] demand that something be done about constant disruption by trollish behavior, the other listmembers will cry "censorship", attack you, and even come to the defense of the troll. [...] The root problem: anti-elitism, or lack of respect for expertise. There is a deeper problem [...] which explains both of the above-elaborated problems. Namely, as a community, Wikipedia lacks the habit or tradition of respect for expertise. As a community, far from being elitist, it is anti-elitist (which, in this context, means that expertise is not accorded any special respect, and snubs and disrespect of expertise is tolerated). This is one of my failures: a policy that I attempted to institute in Wikipedia's first year, but for which I did not muster adequate support, was the policy of respecting and deferring politely to experts. (Those who were there will, I hope, remember that I tried very hard.) }}</ref>

Wikipedians sometimes award one another [[Wikipedia:Barnstars|virtual barnstars]] for good work. These personalized tokens of appreciation reveal a wide range of valued work extending far beyond simple editing to include social support, administrative actions, and types of articulation work.<ref>{{Cite book|title = Articulations of wikiwork: uncovering valued work in Wikipedia through barnstars |author = T. Kriplean |name-list-format = vanc |author2 = I. Beschastnikh |display-authors = 2 |last3 = McDonald |first3 = David W. |chapter-url = http://portal.acm.org/citation.cfm?id=1460563.1460573 |publisher = Proceedings of the ACM |year = 2008 |doi = 10.1145/1460563.1460573 |page = 47 |isbn = 978-1-60558-007-4 |chapter = Articulations of wikiwork }} {{Subscription required|s}}</ref><!-- This is already covered in "Wikipedia community" and might be superfluous here. -->

Wikipedia does not require that its editors and contributors provide identification.<ref name="user identification" /> As Wikipedia grew, "Who writes Wikipedia?" became one of the questions frequently asked on the project.<ref>{{cite journal |title = Power of the Few vs. Wisdom of the Crowd: Wikipedia and the Rise of the Bourgeoisie |publisher = Viktoria Institute |first = Aniket |last = Kittur |year = 2007 |citeseerx =}}</ref> Jimmy Wales once argued that only "a community&nbsp;... a dedicated group of a few hundred volunteers" makes the bulk of contributions to Wikipedia and that the project is therefore "much like any traditional organization".<ref name="blodget">{{cite news |url = http://www.businessinsider.com/2009/1/who-the-hell-writes-wikipedia-anyway |title = Who The Hell Writes Wikipedia, Anyway? |first = Henry |last = Blodget |work = Business Insider |date = January 3, 2009 }}</ref> In 2008, a ''Slate'' magazine article reported that: "According to researchers in Palo Alto, 1 percent of Wikipedia users are responsible for about half of the site's edits."<ref>{{cite news |url = http://www.slate.com/id/2184487 |title = The Wisdom of the Chaperones |date = February 22, 2008 |first = Chris |last = Wilson |work = [[Slate (magazine)|Slate]] |accessdate = August 13, 2014 }}</ref> This method of evaluating contributions was later disputed by [[Aaron Swartz]], who noted that several articles he sampled had large portions of their content (measured by number of characters) contributed by users with low edit counts.<ref>{{cite web |url = http://www.aaronsw.com/weblog/whowriteswikipedia |title = Raw Thought: Who Writes Wikipedia? |first = Aaron |last = Swartz |date = September 4, 2006 |accessdate = February 23, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20140803134036/http://www.aaronsw.com/weblog/whowriteswikipedia |archivedate = August 3, 2014 |df = mdy-all }}</ref>

{{anchor|Decline in participation since 2007}}

The English Wikipedia has {{srlink|Special:Statistics|{{NUMBEROFARTICLES}}}} articles, {{srlink|Special:ActiveUsers|{{NUMBEROFUSERS}}}} registered editors, and {{srlink|Special:ActiveUsers|{{NUMBEROFACTIVEUSERS}}}} active editors. An editor is considered active if they have made one or more edits in the past 30 days.

Editors who fail to comply with Wikipedia cultural rituals, such as [[WP:SIG|signing talk page comments]], may implicitly signal that they are Wikipedia outsiders, increasing the odds that Wikipedia insiders may target or discount their contributions. Becoming a Wikipedia insider involves non-trivial costs: the contributor is expected to learn Wikipedia-specific technological codes, submit to a sometimes convoluted dispute resolution process, and learn a "baffling culture rich with in-jokes and insider references".<ref name="labor squeeze on WP 1" /> Editors who do not log in are in some sense second-class citizens on Wikipedia,<ref name="labor squeeze on WP 1">{{cite journal |title = Wikipedia's Labor Squeeze and its Consequences |publisher = Journal on Telecommunications and High Technology Law |author = Goldman, Eric |volume = 8 }}</ref> as "participants are accredited by members of the wiki community, who have a vested interest in preserving the quality of the work product, on the basis of their ongoing participation",<ref name="legal edu and WP 1">{{cite journal |title = Wikipedia and the Future of Legal Education |author = Noveck, Beth Simone |publisher = Journal of Legal Education |volume = 57 }}</ref> but the contribution histories of anonymous unregistered editors recognized only by their [[IP addresses]] cannot be attributed to a particular editor with certainty.

=== Studies ===

A 2007 study by researchers from [[Dartmouth College]] found that "anonymous and infrequent contributors to Wikipedia [...] are as reliable a source of knowledge as those contributors who register with the site".<ref name="sciam good samaritans 1">{{cite news |url = http://www.sciam.com/article.cfm?id=good-samaritans-are-on-the-money |title = Wikipedia "Good Samaritans" Are on the Money |work = Scientific American |date = October 19, 2007 |accessdate = December 26, 2008 }}</ref> Jimmy Wales stated in 2009 that "(I)t turns out over 50% of all the edits are done by just .7% of the users... 524 people... And in fact the most active 2%, which is 1400 people, have done 73.4% of all the edits."<ref name="blodget" /> However, ''[[Business Insider]]'' editor and journalist [[Henry Blodget]] showed in 2009 that in a random sample of articles, most content in Wikipedia (measured by the amount of contributed text that survives to the latest sampled edit) is created by "outsiders", while most editing and formatting is done by "insiders".<ref name="blodget" />

A 2008 study found that Wikipedians were less agreeable, open, and conscientious than others,<ref name="liebertonline view on WP users 1">Yair Amichai–Hamburger, Naama Lamdan, Rinat Madiel, Tsahi Hayat, [https://archive.today/20121209032032/http://www.liebertonline.com/doi/abs/10.1089/cpb.2007.0225 Personality Characteristics of Wikipedia Members], ''CyberPsychology & Behavior'', December 1, 2008, 11 (6): 679–681; {{DOI|10.1089/cpb.2007.0225}}.</ref><ref name="newscientist view on WP users 1">{{cite web |url = https://www.newscientist.com/article/mg20126883.900-wikipedians-are-closed-and-disagreeable.html |title = Wikipedians are 'closed' and 'disagreeable' |website = New Scientist |accessdate = July 13, 2010 }} {{subscription required|s}}</ref> although a later commentary pointed out serious flaws, including that the data showed higher openness and that the differences with the control group and the samples were small.<ref>{{cite web |url = https://www.psychologytoday.com/blog/unique-everybody-else/201303/the-misunderstood-personality-profile-wikipedia-members |title = The Misunderstood Personality Profile of Wikipedia Members |author = |date = |website = psychologytoday.com |accessdate = June 5, 2016 }}</ref> According to a 2009 study, there is "evidence of growing resistance from the Wikipedia community to new content".<ref name="newscientist WP boom to bust 1">{{cite web |last = Giles |first = Jim |title = After the boom, is Wikipedia heading for bust? |url = https://www.newscientist.com/article/dn17554-after-the-boom-is-wikipedia-heading-for-bust.html |website = New Scientist |date = August 4, 2009 }}</ref>

=== Diversity ===

Several studies have shown that most of the Wikipedia contributors are male. Notably, the results of a Wikimedia Foundation survey in 2008 showed that only 13 percent of Wikipedia editors were female.<ref>{{cite news |last = Cohen |first = Noam |title = Define Gender Gap? Look Up Wikipedia's Contributor List |url = https://www.nytimes.com/2011/01/31/business/media/31link.html?_r=0 |work = The New York Times |publisher = The New York Times Company |accessdate = October 28, 2013 }}</ref> Because of this, universities throughout the United States tried to encourage females to become Wikipedia contributors. Similarly, many of these universities, including [[Yale]] and [[Brown University|Brown]], gave college credit to students who create or edit an article relating to women in science or technology.<ref>{{cite news |url = http://www.cbc.ca/news/canada/toronto/ocad-to-storm-wikipedia-this-fall-1.1412807 |title = OCAD to 'Storm Wikipedia' this fall |work = CBC News |date = August 27, 2013 |accessdate = August 21, 2014 }}</ref> [[Andrew Lih]], a professor and scientist, wrote in ''[[The New York Times]]'' that the reason he thought the number of male contributors outnumbered the number of females so greatly was because identifying as a woman may expose oneself to "ugly, intimidating behavior."<ref>Dimitra Kessenides (December 26, 2017). [[Bloomberg News]] Weekly, "Is Wikipedia 'Woke'". p. 73.</ref> Data has shown that [[Africa]]ns are underrepresented among Wikipedia editors.<ref name="memeb">{{cite web|url=https://memeburn.com/2018/06/wikipedia-wikimania-africa-numbers/|title=The startling numbers behind Africa's Wikipedia knowledge gaps|date=June 21, 2018|website=memeburn.com}}</ref>

== Language editions ==

{{main|List of Wikipedias}}

There are currently 301 language editions of Wikipedia (also called ''language versions'', or simply ''Wikipedias''). As of {{CURRENTMONTHNAME}} {{CURRENTYEAR}}, the six largest, in order of article count, are the {{Wikipedia rank by size/WP|1}}, {{Wikipedia rank by size/WP|2}}, {{Wikipedia rank by size/WP|3}}, {{Wikipedia rank by size/WP|4}}, {{Wikipedia rank by size/WP|5}}, and {{Wikipedia rank by size/WP|6}} Wikipedias.<ref name="WP list of WPs by article 1">{{cite web|url=http://meta.wikimedia.org/wiki/List_of_Wikipedias#All_Wikipedias_ordered_by_number_of_articles|title=Wikipedia:List of Wikipedias|publisher=English Wikipedia|accessdate={{CURRENTMONTHNAME}} {{CURRENTDAY}}, {{CURRENTYEAR}}}}</ref> The second and third largest Wikipedias owe their position to the article-creating [[Internet bot|bot]] [[Lsjbot]], which as of 2013 had created about half the articles in the [[Swedish Wikipedia]], and most of the articles in the [[Cebuano language|Cebuano]] and [[Waray Wikipedia]]s. The latter are both languages of the Philippines.

In addition to the top six, nine other Wikipedias have over one million articles each: [[Russian Wikipedia|Russian]], [[Italian Wikipedia|Italian]], [[Spanish Wikipedia|Spanish]], [[Waray-Waray Wikipedia|Waray-Waray]], [[Polish Wikipedia|Polish]], [[Vietnamese Wikipedia|Vietnamese]], [[Japanese Wikipedia|Japanese]], [[Chinese Wikipedia|Chinese]] and [[Portuguese Wikipedia|Portuguese]]), four more have over 500,000 articles ([[Ukrainian Wikipedia|Ukrainian]], [[Persian Wikipedia|Persian]], [[Catalan Wikipedia|Catalan]] and [[Arabic Wikipedia|Arabic]]), 40 more have over 100,000 articles, and 78 more have over 10,000 articles.<ref name="ListOfWikipedias" /><ref name="WP list of WPs 1">[[meta:List of Wikipedias|List of Wikipedias]]</ref> The largest, the English Wikipedia, has over {{#expr: 0.1*floor({{NUMBEROFARTICLES:R}}/100000)}} million articles. {{as of|2019|01}}, according to Alexa, the English [[subdomain]] (en.wikipedia.org; English Wikipedia) receives approximately 57% of Wikipedia's cumulative traffic, with the remaining split among the other languages (Russian: 9%; Chinese: 6%; Japanese: 6%; Spanish: 5%).<ref name="Alexa siteinfo" />

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{{Largest Wikipedias/graph}}

[[File:TurkishWikipedia block pageviews february-may2017.png|thumb|right|A graph for pageviews of [[Turkish Wikipedia]] shows a large drop of roughly 80% immediately after the [[block of Wikipedia in Turkey]] was imposed in 2017.]]

Since Wikipedia is based on the [[World Wide Web|Web]] and therefore worldwide, contributors to the same language edition may use different dialects or may come from different countries (as is the case for the [[English Wikipedia|English edition]]). These differences may lead to some conflicts over [[American and British English spelling differences|spelling differences]] (e.g. ''colour'' versus ''[[color]]'')<ref name="WP spelling MOS 1">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Spelling |title = Spelling |website = Manual of Style |publisher = Wikipedia |accessdate = May 19, 2007 |date = September 26, 2018 }}</ref> or points of view.<ref name="WP countering bias 1">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Countering_systemic_bias |title = Countering systemic bias |accessdate = May 19, 2007 |date = July 15, 2018 }}</ref>

Though the various language editions are held to global policies such as "neutral point of view", they diverge on some points of policy and practice, most notably on whether images that are not [[free content|licensed freely]] may be used under a claim of [[fair use]].<ref name="WP meta fair use 1">{{cite web |url = http://meta.wikimedia.org/wiki/Fair_use |title = Fair use |publisher = Meta-Wiki |accessdate = July 14, 2007 }}</ref><ref name="WP meta WP images 1">{{cite web |url = http://meta.wikimedia.org/wiki/Images_on_Wikipedia |title = Images on Wikipedia |accessdate = July 14, 2007 }}</ref><ref name="IBM visual WP 1">{{cite journal |url = http://www.research.ibm.com/visual/papers/viegas_hicss_visual_wikipedia.pdf |author = Fernanda B. Viégas |title = The Visual Side of Wikipedia |publisher = Visual Communication Lab, IBM Research |date = January 3, 2007 |accessdate = October 30, 2007 }}</ref>

Jimmy Wales has described Wikipedia as "an effort to create and distribute a free encyclopedia of the highest possible quality to every single person on the planet in their own language".<ref name="WP Wales free multi-lingual encyclopedia">[[Jimmy Wales]], [[:mailarchive:wikipedia-l/2005-March/020469.html|"Wikipedia is an encyclopedia"]], March 8, 2005, &lt;Wikipedia-l@wikimedia.org&gt;</ref> Though each language edition functions more or less independently, some efforts are made to supervise them all. They are coordinated in part by Meta-Wiki, the Wikimedia Foundation's wiki devoted to maintaining all of its projects (Wikipedia and others).<ref name="WP metawiki maintenance 1">{{cite web |url = http://meta.wikimedia.org |title = Meta-Wiki |publisher = Wikimedia Foundation |accessdate = March 24, 2009 }}</ref> For instance, Meta-Wiki provides important statistics on all language editions of Wikipedia,<ref name="WP meta stats 1">{{cite web |url = http://meta.wikimedia.org/wiki/Statistics |title = Meta-Wiki Statistics |publisher = Wikimedia Foundation |accessdate = March 24, 2008 }}</ref> and it maintains a list of articles every Wikipedia should have.<ref name="WP meta articles on all sites 1">{{cite web |url = http://meta.wikimedia.org/wiki/List_of_articles_every_Wikipedia_should_have |title = List of articles every Wikipedia should have |publisher = Wikimedia Foundation |accessdate = March 24, 2008 }}</ref> The list concerns basic content by subject: biography, history, geography, society, culture, science, technology, and mathematics. It is not rare for articles strongly related to a particular language not to have counterparts in another edition. For example, articles about small towns in the United States might be available only in English, even when they meet notability criteria of other language Wikipedia projects.

[[File:User - demography.svg|thumb|left|upright=2.27|Estimation of contributions shares from different regions in the world to different Wikipedia editions]]

Translated articles represent only a small portion of articles in most editions, in part because those editions do not allow fully automated translation of articles.<ref name="WP auto-translations rules 1">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Translation |title = Wikipedia: Translation |website = English Wikipedia |accessdate = February 3, 2007 |date = September 27, 2018 }}</ref> Articles available in more than one language may offer "[[interwiki links]]", which link to the counterpart articles in other editions.

A study published by ''[[PLoS ONE]]'' in 2012 also estimated the share of contributions to different editions of Wikipedia from different regions of the world. It reported that the proportion of the edits made from [[North America]] was 51% for the [[English Wikipedia]], and 25% for the [[simple English Wikipedia]].<ref>{{cite journal |last1 = Yasseri |first1 = Taha |last2 = Sumi |first2 = Robert |last3 = Kertész |first3 = János |authorlink3 = János Kertész |title = Circadian Patterns of Wikipedia Editorial Activity: A Demographic Analysis |journal = [[PLoS ONE]] |date = January 17, 2012 |volume = 7 |issue = 1 |pages = e30091 |doi = 10.1371/journal.pone.0030091 |pmid = 22272279 |pmc = 3260192 |arxiv = 1109.1746 |bibcode = 2012PLoSO...730091Y }}</ref> The Wikimedia Foundation hopes to increase the number of editors in the Global South to 37% by 2015.<ref name="WP global south demographic increase plan 1">{{cite web |title = Wikimedia Foundation 2011–12 Annual Plan |url = http://upload.wikimedia.org/wikipedia/foundation/3/37/2011-12_Wikimedia_Foundation_Plan_FINAL_FOR_WEBSITE_.pdf |publisher = Wikimedia Foundation |page = 8 |accessdate = June 5, 2016 }}</ref>

=== English Wikipedia editor decline ===

On March 1, 2014, ''[[The Economist]]'', in an article titled "The Future of Wikipedia", cited a trend analysis concerning data published by Wikimedia stating that "[t]he number of editors for the English-language version has fallen by a third in seven years."<ref name="economist1">{{cite news |url = https://www.economist.com/news/international/21597959-popular-online-encyclopedia-must-work-out-what-next-wikipeaks |title = The future of Wikipedia: WikiPeaks? |work = The Economist |date = March 1, 2014 |accessdate = March 11, 2014 }}</ref> The attrition rate for active editors in English Wikipedia was cited by ''The Economist'' as substantially in contrast to statistics for Wikipedia in other languages (non-English Wikipedia). ''The Economist'' reported that the number of contributors with an average of five or more edits per month was relatively constant since 2008 for Wikipedia in other languages at approximately 42,000 editors within narrow seasonal variances of about 2,000 editors up or down. The number of active editors in English Wikipedia, by sharp comparison, was cited as peaking in 2007 at approximately 50,000 and dropping to 30,000 by the start of 2014.

Should attrition continue unabated at the quoted trend rate of approximately 20,000 editors lost within a seven-year stretch, by 2021 there will be only 10,000 active editors on English Wikipedia.<ref name="economist1" /> In contrast, the trend analysis published in ''The Economist'' presents Wikipedia in other languages (non-English Wikipedia) as successful in retaining their active editors on a renewable and sustained basis, with their numbers remaining relatively constant at approximately 42,000.<ref name="economist1" /> No comment was made concerning which of the differentiated edit policy standards from Wikipedia in other languages (non-English Wikipedia) would provide a possible alternative to English Wikipedia for effectively ameliorating substantial editor attrition rates on the English-language Wikipedia.<ref>Andrew Lih. ''Wikipedia''. Alternative edit policies at Wikipedia in other languages.</ref>

== Reception ==

{{See also|Academic studies about Wikipedia|Criticism of Wikipedia}}

{{Update-section|date=March 2018}}

Several Wikipedians have [[Criticism of Wikipedia#Excessive regulation|criticized Wikipedia's large and growing regulation]], which includes over 50 policies and nearly 150,000 words {{as of|2014|lc=y}}.<ref name="bureaucracy">{{cite news |url = http://www.slate.com/articles/technology/future_tense/2014/06/wikipedia_s_bureaucracy_problem_and_how_to_fix_it.html |title = The Unbearable Bureaucracy of Wikipedia |last = Jemielniak |first = Dariusz |publisher = [[Slate (magazine)|Slate]] |date = June 22, 2014 |accessdate = August 18, 2014 }}</ref><ref>D. Jemielniak, ''Common Knowledge'', Stanford University Press, 2014.</ref>

Critics have stated that Wikipedia exhibits [[systemic bias]]. In 2010, columnist and journalist [[Edwin Black]] criticized Wikipedia for being a mixture of "truth, half truth, and some falsehoods".<ref name=EdwinBlack>[[Edwin Black|Black, Edwin]] (April 19, 2010) [http://historynewsnetwork.org/article/125437 Wikipedia – The Dumbing Down of World Knowledge] {{webarchive |url=https://web.archive.org/web/20160909210831/http://historynewsnetwork.org/article/125437 |date=September 9, 2016 }}, [[History News Network]] Retrieved October 21, 2014</ref> Articles in ''[[The Chronicle of Higher Education]]'' and ''[[The Journal of Academic Librarianship]]'' have criticized Wikipedia's [[WP:Undue|Undue Weight]] policy, concluding that the fact that Wikipedia explicitly is not designed to provide correct information about a subject, but rather focus on all the major viewpoints on the subject and give less attention to minor ones, creates omissions that can lead to false beliefs based on incomplete information.<ref>Messer-Kruse, Timothy (February 12, 2012) [http://chronicle.com/article/The-Undue-Weight-of-Truth-on/130704/ The 'Undue Weight' of Truth on Wikipedia] {{webarchive |url=https://web.archive.org/web/20161218162359/http://chronicle.com/article/The-Undue-Weight-of-Truth-on/130704/ |date=December 18, 2016 }} ''[[The Chronicle of Higher Education]]'' Retrieved March 27, 2014</ref><ref>Colón-Aguirre, Monica & Fleming-May, Rachel A. (October 11, 2012) [http://faculty.washington.edu/jwj/lis521/colon%20wikipedia.pdf "You Just Type in What You Are Looking For": Undergraduates' Use of Library Resources vs. Wikipedia] {{webarchive |url=https://web.archive.org/web/20160419031904/http://faculty.washington.edu/jwj/lis521/colon%20wikipedia.pdf |date=April 19, 2016 }} (p. 392) ''[[The Journal of Academic Librarianship]]'' Retrieved March 27, 2014</ref><ref>Bowling Green News (February 27, 2012) [http://www.bgsu.edu/news/2012/02/wikipedia-experience-sparks-national-debate.html Wikipedia experience sparks national debate] {{webarchive |url=https://web.archive.org/web/20160827120800/http://www.bgsu.edu/news/2012/02/wikipedia-experience-sparks-national-debate.html |date=August 27, 2016 }} [[Bowling Green State University]] Retrieved March 27, 2014</ref>

Journalists [[Oliver Kamm]] and [[Edwin Black]] noted (in 2010 and 2011 respectively) how articles are dominated by the loudest and most persistent voices, usually by a group with an "ax to grind" on the topic.<ref name=EdwinBlack /><ref name=okw>[https://web.archive.org/web/20110814104256/http://www.timesonline.co.uk/tol/comment/columnists/guest_contributors/article2267665.ece Wisdom? More like dumbness of the crowds | Oliver Kamm – Times Online (archive version 2011-08-14)] ([http://oliverkamm.typepad.com/blog/2007/08/wisdom-more-lik.html Author's own copy] {{webarchive |url=https://web.archive.org/web/20160905131644/http://oliverkamm.typepad.com/blog/2007/08/wisdom-more-lik.html |date=September 5, 2016 }})</ref> A 2008 article in ''[[Education Next]]'' Journal concluded that as a resource about controversial topics, Wikipedia is subject to manipulation and [[spin (public relations)|spin]].<ref name=Petrilli>J. Petrilli, Michael (Spring 2008/Vol. 8, No. 2) [http://educationnext.org/wikipedia-or-wickedpedia/ Wikipedia or Wickedpedia?] {{webarchive |url=https://web.archive.org/web/20161121024654/http://educationnext.org/wikipedia-or-wickedpedia/ |date=November 21, 2016 }}, [[Education Next]] Retrieved October 22, 2014</ref>

In 2006, the ''Wikipedia Watch'' criticism website listed dozens of examples of [[plagiarism]] in the English Wikipedia.<ref name="wwplagiarism" />

=== Accuracy of content ===

{{Main|Reliability of Wikipedia}}

Articles for traditional encyclopedias such as ''[[Encyclopædia Britannica]]'' are carefully and deliberately written by experts, lending such encyclopedias a reputation for accuracy.<ref>{{cite news |url = http://archive.wired.com/culture/lifestyle/news/2005/12/69844 |title = Wikipedia, Britannica: A Toss-Up |work = Wired |date = December 15, 2005 |accessdate = August 8, 2015 |agency = Associated Press }}</ref> However, a peer review in 2005 of forty-two scientific entries on both Wikipedia and ''Encyclopædia Britannica'' by the science journal ''Nature'' found few differences in accuracy, and concluded that "the average science entry in Wikipedia contained around four inaccuracies; ''Britannica'', about three."<ref name="GilesJ2005Internet" /> Reagle suggested that while the study reflects "a topical strength of Wikipedia contributors" in science articles, "Wikipedia may not have fared so well using a random sampling of articles or on humanities subjects."<ref name="Reagle, pp. 165–166"/> Others raised similar critiques.<ref name="Orlowski2005"/> The findings by ''Nature'' were disputed by ''Encyclopædia Britannica'',<ref name="corporate.britannica.com" /><ref name="nature.com britannica response 1">{{cite web |url = http://www.nature.com/press_releases/Britannica_response.pdf?item |format = PDF |title = Encyclopaedia Britannica and Nature: a response |accessdate = July 13, 2010 }}</ref> and in response, ''Nature'' gave a rebuttal of the points raised by ''Britannica''.<ref name="nature.com">{{cite web |website = Nature |url = http://www.nature.com/nature/britannica/index.html |title = Nature's responses to Encyclopaedia Britannica |date = March 30, 2006 |accessdate = February 25, 2018|archiveurl=https://web.archive.org/web/20170515025717/http://www.nature.com/nature/britannica/index.html|archivedate=May 15, 2017}}</ref> In addition to the point-for-point disagreement between these two parties, others have examined the sample size and selection method used in the ''Nature'' effort, and suggested a "flawed study design" (in ''Nature''{{'}}s manual selection of articles, in part or in whole, for comparison), absence of statistical analysis (e.g., of reported [[confidence interval]]s), and a lack of study "statistical power" (i.e., owing to small [[sample size]], 42 or 4 × 10<sup>1</sup> articles compared, vs >10<sup>5</sup> and >10<sup>6</sup> set sizes for ''Britannica'' and the English Wikipedia, respectively).<ref>See author acknowledged comments in response to the citation of the ''Nature'' study, at ''PLoS ONE'', 2014, "Citation of fundamentally flawed ''Nature'' quality 'study' ", In response to T. Yasseri et al. (2012) Dynamics of Conflicts in Wikipedia, Published June 20, 2012, {{DOI|10.1371/journal.pone.0038869}}, see {{cite web |url = http://www.plosone.org/annotation/listThread.action?root%3D80078 |title = Archived copy |accessdate = July 22, 2014 |deadurl = yes |archiveurl = https://web.archive.org/web/20160116210930/http://www.plosone.org/annotation/listThread.action?root=80078 |archivedate = January 16, 2016 |df = mdy-all }}, accessed July 21, 2014.</ref>

As a consequence of the open structure, Wikipedia "makes no guarantee of validity" of its content, since no one is ultimately responsible for any claims appearing in it.<ref name="WP general disclaimer 1">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:General_disclaimer |title = Wikipedia:General disclaimer |publisher = English Wikipedia |accessdate = April 22, 2008 |date = September 18, 2018 }}</ref> Concerns have been raised by ''PC World'' in 2009 regarding the lack of [[accountability]] that results from users' anonymity,<ref name="WikipediaWatch" /> the insertion of false information,<ref name="pcworld WP blunders 1">{{cite web |last = Raphel |first = JR |url = http://www.pcworld.com/article/170874/the_15_biggest_wikipedia_blunders.html |title = The 15 Biggest Wikipedia Blunders |website = [[PC World (magazine)|PC World]] |accessdate = September 2, 2009 |date = August 26, 2009 }}</ref> [[Vandalism on Wikipedia|vandalism]], and similar problems.

Economist [[Tyler Cowen]] wrote: "If I had to guess whether Wikipedia or the median refereed journal article on economics was more likely to be true, after a not so long think I would opt for Wikipedia." He comments that some traditional sources of non-fiction suffer from systemic biases and novel results, in his opinion, are over-reported in journal articles and relevant information is omitted from news reports. However, he also cautions that errors are frequently found on Internet sites, and that academics and experts must be vigilant in correcting them.<ref name="tnr experts vigilant in correcting WP 1">{{cite web |url = http://www.tnr.com/story.html?id=82eb5d70-13bd-4086-9ec0-cb0e9e8411b3 |archiveurl = https://web.archive.org/web/20080318103017/http://www.tnr.com/story.html?id=82eb5d70-13bd-4086-9ec0-cb0e9e8411b3 |archivedate = March 18, 2008 |title = Cooked Books |first = Tyler |last = Cowen |website = The New Republic |date = March 14, 2008 |accessdate = December 26, 2008 }}</ref>

Critics argue that Wikipedia's open nature and a lack of proper sources for most of the information makes it unreliable.<ref name="TNY reliability issues 1">{{cite news |author = [[Stacy Schiff]] |date = July 31, 2006 |title = Know It All |work = [[The New Yorker]] }}</ref> Some commentators suggest that Wikipedia may be reliable, but that the reliability of any given article is not clear.<ref name="AcademiaAndWikipedia" /> Editors of traditional [[reference work]]s such as the ''Encyclopædia Britannica'' have questioned the project's [[utility]] and status as an encyclopedia.<ref name="McHenry_2004" /> Wikipedia co-founder [[Jimmy Wales]] has claimed that Wikipedia has largely avoided the problem of "fake news" because the Wikipedia community regularly debates the quality of sources in articles.<ref>{{Cite news|url=https://www.npr.org/2018/04/27/606393983/wikipedia-founder-says-internet-users-are-adrift-in-the-fake-news-era|title=Wikipedia Founder Says Internet Users Are Adrift In The 'Fake News' Era|work=NPR.org|access-date=May 1, 2018|language=en|archive-url=https://web.archive.org/web/20180625213220/https://www.npr.org/2018/04/27/606393983/wikipedia-founder-says-internet-users-are-adrift-in-the-fake-news-era|archive-date=June 25, 2018|dead-url=no}}</ref>

{{external media | width = 210px | align = right | video1 = [http://www.dw.de/inside-wikipedia-attack-of-the-pr-industry/av-17745881 Inside Wikipedia – Attack of the PR Industry], [[Deutsche Welle]], 7:13 mins<ref name="dw">{{cite web |title = Inside Wikipedia – Attack of the PR Industry |publisher = [[Deutsche Welle]] |date = June 30, 2014 |url = http://www.dw.de/inside-wikipedia-attack-of-the-pr-industry/av-17745881 |accessdate = July 2, 2014 }}</ref> }}

Wikipedia's open structure inherently makes it an easy target for Internet [[troll (Internet)|trolls]], [[Spam (electronic)|spammers]], and various forms of paid advocacy seen as counterproductive to the maintenance of a neutral and verifiable online encyclopedia.<ref name="Torsten_Kleinz" /><ref name="citizendium WP trolling issues 1">{{cite web |title = Toward a New Compendium of Knowledge (longer version) |url = http://www.citizendium.org/essay.html |website = Citizendium |accessdate = October 10, 2006 |archiveurl = https://web.archive.org/web/20061011230402/http://www.citizendium.org/essay.html |archive-date = October 11, 2006 }}</ref>

In response to [[Conflict-of-interest editing on Wikipedia|paid advocacy editing]] and undisclosed editing issues, Wikipedia was reported in an article in ''The Wall Street Journal'', to have strengthened its rules and laws against undisclosed editing.<ref name="ReferenceA">{{cite web |title = Wikipedia Strengthens Rules Against Undisclosed Editing |url = https://blogs.wsj.com/digits/2014/06/16/wikipedia-strengthens-rules-against-undisclosed-editing/ |author = Elder, Jeff |publisher = [[The Wall Street Journal]] |date = June 16, 2014 }}</ref> The article stated that: "Beginning Monday [from the date of article, June 16, 2014], changes in Wikipedia's terms of use will require anyone paid to edit articles to disclose that arrangement. [[Katherine Maher]], the nonprofit Wikimedia Foundation's chief communications officer, said the changes address a sentiment among volunteer editors that, 'we're not an advertising service; we're an encyclopedia.{{'"}}<ref name="ReferenceA" /><ref name="DeathByWikipedia" /><ref name="cnet politicians and WP 1">{{cite web |url = http://news.cnet.com/8301-10784_3-6032713-7.html |title = Politicians notice Wikipedia |publisher = CNET |author = Kane, Margaret |date = January 30, 2006 |accessdate = January 28, 2007 }}</ref><ref name="msnbc MS cash for WP edits 1">{{cite web |url = http://www.msnbc.msn.com/id/16775981 |title = Microsoft offers cash for Wikipedia edit |publisher = MSNBC |author = Bergstein, Brian |authorlink = Brian Bergstein |date = January 23, 2007 |accessdate = February 1, 2007 }}</ref><ref name="Seeing Corporate Fingerprints" /> These issues, among others, had been parodied since the first decade of Wikipedia, notably by [[Stephen Colbert]] on ''[[The Colbert Report]]''.<ref name="wikiality" />

A Harvard law textbook, ''Legal Research in a Nutshell'' (2011), cites Wikipedia as a "general source" that "can be a real boon" in "coming up to speed in the law governing a situation" and, "while not authoritative, can provide basic facts as well as leads to more in-depth resources".<ref name="Nutshell in-depth resources">{{cite book|title=Legal Research in a Nutshell|last=Cohen|first=Morris|author2=Olson, Kent|publisher=Thomson Reuters|year=2010|isbn=978-0-314-26408-4|edition=10th|location=St. Paul, Minnesota|pages=32–34}}</ref>

=== Discouragement in education ===

Most university [[lecturer]]s discourage students from citing any encyclopedia in [[Academia|academic work]], preferring [[primary source]]s;<ref name="WideWorldOfWikipedia" /> some specifically prohibit Wikipedia citations.<ref name="insidehighered against WP 1">{{Cite journal |last1 = Waters |first1 = N.L. |title = Why you can't cite Wikipedia in my class |doi = 10.1145/1284621.1284635 |journal = Communications of the ACM |volume = 50 |issue = 9 |page = 15 |year = 2007 |pmid = |pmc = |bibcode = 1985CACM...28...22S |citeseerx = }}</ref><ref name="insidehighered wiki no cite">{{cite news |first = Scott |last = Jaschik |title = A Stand Against Wikipedia |url = http://www.insidehighered.com/news/2007/01/26/wiki |publisher = Inside Higher Ed |date = January 26, 2007 |accessdate = January 27, 2007 }}</ref> Wales stresses that encyclopedias of any type are not usually appropriate to use as citable sources, and should not be relied upon as authoritative.<ref name="AWorkInProgress" /> Wales once (2006 or earlier) said he receives about ten [[email]]s weekly from students saying they got failing grades on papers because they cited Wikipedia; he told the students they got what they deserved. "For God's sake, you're in college; don't cite the encyclopedia," he said.<ref name="Jimmy Wales don't cite WP 1">"Jimmy Wales", ''Biography Resource Center Online''. (Gale, 2006.)</ref>

In February 2007, an article in ''[[The Harvard Crimson]]'' newspaper reported that a few of the professors at [[Harvard University]] were including Wikipedia articles in their [[syllabus|syllabi]], although without realizing the articles might change.<ref name="thecrimson wiki debate">Child, Maxwell L., [http://www.thecrimson.com/article.aspx?ref=517305 "Professors Split on Wiki Debate"] {{webarchive |url=https://web.archive.org/web/20081220125910/http://www.thecrimson.com/article.aspx?ref=517305 |date=December 20, 2008 }}, ''The Harvard Crimson'', February 26, 2007.</ref> In June 2007, former president of the [[American Library Association]] [[Michael Gorman (librarian)|Michael Gorman]] condemned Wikipedia, along with [[Google]],<ref name="stothart" /> stating that academics who endorse the use of Wikipedia are "the intellectual equivalent of a dietitian who recommends a steady diet of Big Macs with everything".

==== Medical information ====

{{anchor|Medical information}}

{{See also|Health information on Wikipedia}}

On March 5, 2014, Julie Beck writing for ''The Atlantic'' magazine in an article titled "Doctors' #1 Source for Healthcare Information: Wikipedia", stated that

"Fifty percent of physicians look up conditions on the (Wikipedia) site, and some are editing articles themselves to improve the quality of available information."<ref name="Julie Beck 2014">Julie Beck. "Doctors' #1 Source for Healthcare Information: Wikipedia". ''The Atlantic'', March 5, 2014.</ref> Beck continued to detail in this article new programs of [[Amin Azzam]] at the University of San Francisco to offer medical school courses to medical students for learning to edit and improve [[Health information on Wikipedia|Wikipedia articles on health-related issues]], as well as internal quality control programs within Wikipedia organized by [[James Heilman]] to improve a group of 200 health-related articles of central medical importance up to Wikipedia's highest standard of articles using its Featured Article and Good Article peer review evaluation process.<ref name="Julie Beck 2014" /> In a May 7, 2014, follow-up article in ''The Atlantic'' titled "Can Wikipedia Ever Be a Definitive Medical Text?", Julie Beck quotes [[Wikipedia:WikiProject Medicine|WikiProject Medicine]]'s James Heilman as stating: "Just because a reference is peer-reviewed doesn't mean it's a high-quality reference."<ref name="theatlantic.com">{{cite web |last = Green |first = Emma |url = https://www.theatlantic.com/health/archive/2014/05/can-wikipedia-ever-be-a-definitive-medical-text/361822/ |title = Can Wikipedia Ever Be a Definitive Medical Text? – Julie Beck |publisher = The Atlantic |date = May 7, 2014 |accessdate = June 14, 2014 }}</ref> Beck added that: "Wikipedia has its own peer review process before articles can be classified as 'good' or 'featured.' Heilman, who has participated in that process before, says 'less than 1 percent' of Wikipedia's medical articles have passed."<ref name="theatlantic.com" />

=== Quality of writing ===

In 2008, researchers at [[Carnegie Mellon University]] found that the quality of a Wikipedia article would suffer rather than gain from adding more writers when the article lacked appropriate explicit or implicit coordination.<ref>{{cite book |last1 = Kittur |first1 = Aniket |last2 = Kraut |first2 = Robert E. |chapter = Harnessing the wisdom of crowds in Wikipedia: quality through coordination |title = Proceedings of the 2008 ACM conference on Computer supported cooperative work |pages = 37–46 |place = New York |publisher = ACM |date = 2008 |doi = 10.1145/1460563.1460572 |isbn = 978-1-60558-007-4 |chapter-url = http://dl.acm.org/citation.cfm?id=1460572 }}{{Dead link|date=December 2016 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> For instance, when contributors rewrite small portions of an entry rather than making full-length revisions, high- and low-quality content may be intermingled within an entry. [[Roy Rosenzweig]], a history professor, stated that ''American National Biography Online'' outperformed Wikipedia in terms of its "clear and engaging prose", which, he said, was an important aspect of good historical writing.<ref name="Rosenzweig" /> Contrasting Wikipedia's treatment of [[Abraham Lincoln]] to that of [[American Civil War|Civil War]] historian [[James M. McPherson|James McPherson]] in ''American National Biography Online'', he said that both were essentially accurate and covered the major episodes in Lincoln's life, but praised "McPherson's richer contextualization [...] his artful use of quotations to capture Lincoln's voice [...] and [...] his ability to convey a profound message in a handful of words." By contrast, he gives an example of Wikipedia's prose that he finds "both verbose and dull". Rosenzweig also criticized the "waffling—encouraged by the NPOV policy—[which] means that it is hard to discern any overall interpretive stance in Wikipedia history". While generally praising the article on [[William Clarke Quantrill]], he quoted its conclusion as an example of such "waffling", which then stated: "Some historians [...] remember him as an opportunistic, bloodthirsty outlaw, while others continue to view him as a daring soldier and local folk hero."<ref name="Rosenzweig" />

Other critics have made similar charges that, even if Wikipedia articles are factually accurate, they are often written in a poor, almost unreadable style. Frequent Wikipedia critic Andrew Orlowski commented, "Even when a Wikipedia entry is 100 per cent factually correct, and those facts have been carefully chosen, it all too often reads as if it has been translated from one language to another then into a third, passing an illiterate translator at each stage."<ref name="theregister Wales WP founder on quality 1">{{cite web |url = https://www.theregister.co.uk/2005/10/18/wikipedia_quality_problem/page2.html |title = Wikipedia founder admits to serious quality problems |author = Andrew Orlowski |website = The Register |date = October 18, 2005 |accessdate = September 30, 2007 }}</ref> A study of Wikipedia articles on [[cancer]] was conducted in 2010 by Yaacov Lawrence of the Kimmel Cancer Center at [[Thomas Jefferson University]]. The study was limited to those articles that could be found in the ''Physician Data Query'' and excluded those written at the "start" class or "stub" class level. Lawrence found the articles accurate but not very readable, and thought that "Wikipedia's lack of readability (to non-college readers) may reflect its varied origins and haphazard editing".<ref name="upi accuracy 1">{{cite news |url = https://www.sciencedaily.com/releases/2010/06/100601114641.htm |title = Cancer information on Wikipedia is accurate, but not very readable, study finds |work = Science Daily |date = June 2, 2010 |accessdate = December 31, 2010 }}</ref> ''The Economist'' argued that better-written articles tend to be more reliable: "inelegant or ranting prose usually reflects muddled thoughts and incomplete information".<ref name="economist incomplete info">{{cite news |url = http://www.economist.com/node/8820422?story_id=8820422 |title = Fact or fiction? Wikipedia's variety of contributors is not only a strength |work = The Economist |date = March 10, 2007 |accessdate = December 31, 2010 }}</ref>

To assess Wikipedia articles various quality measures related to [[credibility]], [[Completeness (knowledge bases)|completeness]], [[Objectivity (science)|objectivity]], [[readability]], [[relevance]], [[Writing style|style]] and [[timeliness]] can be used.<ref name="measures2019">{{cite book |last1=Lewoniewski |first1=Włodzimierz |year=2019 |title=Measures for Quality Assessment of Articles and Infoboxes in Multilingual Wikipedia |url=https://www.researchgate.net/publication/330087836 |journal=Lecture Notes in Business Information Processing |volume=339 |issue= |pages=619–633 |doi=10.1007/978-3-030-04849-5_53 |isbn=978-3-030-04849-5}}</ref>

=== Coverage of topics and systemic bias ===

{{See also|Notability in the English Wikipedia|Criticism of Wikipedia#Systemic bias in coverage}}

{{Update|[[:d:Wikidata:Statistics/Wikipedia]]|date=March 2017}}

Wikipedia seeks to create a summary of all human knowledge in the form of an online encyclopedia, with each topic covered encyclopedically in one article. Since it has [[terabyte]]s of disk space, it can have far more topics than can be covered by any printed encyclopedia.<ref name="WP advantages over trad media 1">{{srlink|Wikipedia:PAPER}}</ref> The exact degree and manner of coverage on Wikipedia is under constant review by its editors, and disagreements are not uncommon (see [[deletionism and inclusionism in Wikipedia|deletionism and inclusionism]]).<ref name="Economist disagreements not uncommon">{{cite news |title = The battle for Wikipedia's soul |url = http://www.economist.com/printedition/displaystory.cfm?story_id=10789354 |work = The Economist |date = 2008-03-06 |accessdate = 2008-03-07 |ISSN=0013-0613}}</ref><ref name="telegraph WP torn apart 1">{{cite news |title = Wikipedia: an online encyclopedia torn apart |first = Ian |last = Douglas |work = The Daily Telegraph |location = London |date = November 10, 2007 |url = https://www.telegraph.co.uk/technology/3354752/Wikipedia-an-online-encyclopedia-torn-apart.html |accessdate = November 23, 2010 }}</ref> Wikipedia contains materials that some people may find objectionable, offensive, or pornographic because [[Wikipedia:Wikipedia is not#Wikipedia is not censored|Wikipedia is not censored]]. The policy has sometimes proved controversial: in 2008, Wikipedia rejected an online petition against the inclusion of [[Online petition on Wikipedia Muhammad article|images of Muhammad]] in the [[English Wikipedia|English edition]] of its [[Muhammad]] article, citing this policy. The presence of politically, religiously, and pornographically sensitive materials in Wikipedia has led to the [[censorship of Wikipedia]] by national authorities in [[China]]<ref name="Taylor" /> and [[Pakistan]],<ref name="washington post state censorship 1">{{cite news |url = https://www.washingtonpost.com/wp-dyn/content/article/2010/05/20/AR2010052005073.html |title = Pakistan blocks YouTube a day after shutdown of Facebook over Muhammad issue |first = Karin |last = Bruilliard |work = The Washington Post |date = May 21, 2010 |accessdate = October 24, 2011 }}</ref> amongst other countries.

[[File:Wikipedia content by subject.png|thumb|upright=2.27|Pie chart of Wikipedia content by subject as of January 2008<ref name=Kittur2009 />]]

A 2008 study conducted by researchers at Carnegie Mellon University and Palo Alto Research Center gave a distribution of topics as well as growth (from July 2006 to January 2008) in each field:<ref name="Kittur2009" />

* Culture and the arts: 30% (210%)

* Biographies and persons: 15% (97%)

* Geography and places: 14% (52%)

* Society and social sciences: 12% (83%)

* History and events: 11% (143%)

* Natural and physical sciences: 9% (213%)

* Technology and the applied sciences: 4% (−6%)

* Religions and belief systems: 2% (38%)

* Health: 2% (42%)

* Mathematics and logic: 1% (146%)

* Thought and philosophy: 1% (160%)

These numbers refer only to the quantity of articles: it is possible for one topic to contain a large number of short articles and another to contain a small number of large ones. Through its "[[Wikipedia:Wikipedia Loves Libraries|Wikipedia Loves Libraries]]" program, Wikipedia has partnered with major public libraries such as the [[New York Public Library for the Performing Arts]] to expand its coverage of underrepresented subjects and articles.<ref name="NYT subjects and articles">{{cite news |url = https://www.nytimes.com/2011/10/21/theater/editing-wikipedia-at-the-new-york-public-library-for-the-performing-arts.html |title = Wikipedia's Deep Dive Into a Library Collection |last = Petrusich |first = Amanda |work = The New York Times |date = October 20, 2011 |accessdate = October 28, 2011 }}</ref>

A 2011 study conducted by researchers at the [[University of Minnesota]] indicated that male and female editors focus on different coverage topics. There was a greater concentration of females in the People and Arts category, while males focus more on Geography and Science.<ref>{{cite journal |last = Lam |first = Shyong (Tony) K.|author2 = Anuradha Uduwage |author3 = Zhenhua Dong |author4 = Shilad Sen |author5 = David R. Musicant |author6 = Loren Terveen |author7 = John Riedl |title = WP: Clubhouse? An Exploration of Wikipedia's Gender Imbalance |journal = WikiSym 2011 |date = October 3–5, 2011 |page = 4 |url = http://files.grouplens.org/papers/wp-gender-wikisym2011.pdf }}</ref>

==== Coverage of topics and selection bias ====

Research conducted by Mark Graham of the [[Oxford Internet Institute]] in 2009 indicated that the geographic distribution of article topics is highly uneven. Africa is most underrepresented.<ref>Mark Graham, [https://web.archive.org/web/20161002051150/http://zerogeography.net/post/144973716228/mapping-the-geographies-of-wikipedia-content Mapping the Geographies of Wikipedia Content], ''Zerogeography.net'' (November 12, 2009).</ref> Across 30 language editions of Wikipedia, historical articles and sections are generally Eurocentric and focused on recent events.<ref>{{Cite journal |last = Strohmaier |first = Markus |date = March 6, 2017 |others = |title = Multilingual historical narratives on Wikipedia |journal = |volume = |pages = |doi = 10.7802/1411 |quote = Wikipedia narratives about national histories (i) are skewed towards more recent events (recency bias) and (ii) are distributed unevenly across the continents with significant focus on the history of European countries (Eurocentric bias). |url = https://datorium.gesis.org/xmlui/handle/10.7802/1411 |publisher = GESIS Data Archive }}</ref>

An editorial in ''[[The Guardian]]'' in 2014 noted that [[List of pornographic actresses by decade|women porn stars]] are better covered than [[women writer]]s as a further example.<ref name=GuardianAugust2014>''[[The Guardian]]'' 2014 (London) [https://www.theguardian.com/commentisfree/2014/aug/07/guardian-view-wikipedia-evolving-truth The Guardian view on Wikipedia: evolving truth] {{webarchive |url=https://web.archive.org/web/20161112212758/https://www.theguardian.com/commentisfree/2014/aug/07/guardian-view-wikipedia-evolving-truth |date=November 12, 2016 }}</ref> Data has also shown that Africa-related material often faces omission; a knowledge gap that a July 2018 Wikimedia conference in [[Cape Town]] sought to address.<ref name="memeb"/>

==== Systemic bias ====

When multiple editors contribute to one topic or set of topics, [[systemic bias]] may arise, due to the demographic backgrounds of the editors. In 2011, Wales noted that the unevenness of coverage is a reflection of the demography of the editors, which predominantly consists of highly educated young males in the developed world (see previously).<ref name="wiki-women">{{cite news |title = Wikipedia seeks women to balance its 'geeky' editors |author = Kevin Rawlinson |newspaper = The Independent |url = https://www.independent.co.uk/life-style/gadgets-and-tech/news/wikipedia-seeks-women-to-balance-its-geeky-editors-2333605.html |date = August 8, 2011 |accessdate = April 5, 2012 }}</ref> The October 22, 2013, essay by Tom Simonite in MIT's ''Technology Review'' titled "The Decline of Wikipedia" discussed the effect of systemic bias and [[Criticism of Wikipedia#Excessive regulation|policy creep]] on the [[#Decline in participation since 2009|downward trend in the number of editors]].<ref name="Simonite-2013" />

[[Bias in Wikipedia|Systemic bias on Wikipedia]] may follow that of culture generally, for example favoring certain nationalities, ethnicities or majority religions.<ref name="Quilter">{{cite web |url = http://works.bepress.com/cgi/viewcontent.cgi?article=1035&context=laura_quilter |title = Systemic Bias in Wikipedia: What It Looks Like, and How to Deal with It |author = Quilter, Laura |publisher = University of Massachusetts – Amherst |date = October 24, 2012 |accessdate = November 26, 2012 }}</ref> It may more specifically follow the biases of [[Internet culture]], inclining to being young, male, English-speaking, educated, technologically aware, and wealthy enough to spare time for editing. Biases of its own may include over-emphasis on topics such as pop culture, technology, and current events.<ref name="Quilter" />

[[Taha Yasseri]] of the [[University of Oxford]], in 2013, studied the statistical trends of systemic bias at Wikipedia introduced by editing conflicts and their resolution.<ref>"[https://www.technologyreview.com/s/517101/edit-wars-reveal-the-10-most-controversial-topics-on-wikipedia/ Edit Wars Reveal the 10 Most Controversial Topics on Wikipedia]", MIT Technology Review, July 17, 2013.</ref><ref name="autogenerated3">{{citation|ssrn = 2269392 |title = The Most Controversial Topics in Wikipedia: A Multilingual and Geographical Analysis by Taha Yasseri, Anselm Spoerri, Mark Graham, Janos Kertesz :: SSRN |doi = 10.2139/ssrn.2269392 |date = May 23, 2013 |arxiv = 1305.5566 |last1 = Yasseri |first1 = Taha |last2 = Spoerri |first2 = Anselm |last3 = Graham |first3 = Mark |last4 = Kertesz |first4 = Janos }}</ref> His research examined the [[counterproductive work behavior]] of edit warring. Yasseri contended that simple reverts or "undo" operations were not the most significant measure of counterproductive behavior at Wikipedia and relied instead on the [[statistical measurement]] of detecting "reverting/reverted pairs" or "mutually reverting edit pairs". Such a "mutually reverting edit pair" is defined where one editor reverts the edit of another editor who then, in sequence, returns to revert the first editor in the "mutually reverting edit pairs". The results were tabulated for several language versions of Wikipedia. The English Wikipedia's three largest conflict rates belonged to the articles ''[[George W. Bush]]'', ''[[Anarchism]]'' and ''[[Muhammad]]''.<ref name="autogenerated3" /> By comparison, for the German Wikipedia, the three largest conflict rates at the time of the [[Oxford]] study were for the articles covering (i) ''[[Croatia]]'', (ii) ''[[Scientology]]'' and (iii) ''[[9/11 conspiracy theories]]''.<ref name="autogenerated3"/>

Researchers from [[Washington University]] developed a statistical model to measure systematic bias in the behavior of Wikipedia's users regarding controversial topics. The authors focused on behavioral changes of the encyclopedia's administrators after assuming the post, writing that systematic bias occurred after the fact.<ref>

{{cite conference |url = https://dl.acm.org/citation.cfm?id=2505566 |title = Manipulation among the arbiters of collective intelligence: How Wikipedia administrators mold public opinion |last1 = Das |first1 = Sanmay |last2 = Allen |first2 = Lavoie |last3 = Malik |first3 = Magdon-Ismail |date = November 1, 2013 |publisher = ACM |book-title = CIKM '13 Proceedings of the 22nd ACM international conference on Information & Knowledge Management |pages = 1097–1106 |location = San Francisco, California |doi = 10.1145/2505515.2505566 |isbn = 978-1-4503-2263-8 }}


{{cite journal |last1 = Das |first1 = Sanmay |last2 = Allen |first2 = Lavoie |last3 = Malik |first3 = Magdon-Ismail |title = Manipulation among the arbiters of collective intelligence: How Wikipedia administrators mold public opinion |journal = ACM Transactions on the Web |volume = 10 |issue = 4 |pages = 24 |date = December 24, 2016 |doi = 10.1145/3001937 }}


=== Explicit content ===

{{See also|Internet Watch Foundation and Wikipedia|Reporting of child pornography images on Wikimedia Commons}}

{{Selfref|"Wikipedia censorship" redirects here. For the government censorship of Wikipedia, see [[Censorship of Wikipedia]]. For Wikipedia's policy concerning censorship, see [[Wikipedia:Wikipedia is not censored]]}}

Wikipedia has been criticized for allowing information of graphic content. Articles depicting what some critics have called objectionable content (such as [[Feces]], [[Cadaver]], [[Human penis]], [[Vulva]], and [[Nudity]]) contain graphic pictures and detailed information easily available to anyone with access to the internet, including children.

The site also includes [[sexual content]] such as images and videos of [[masturbation]] and [[ejaculation]], [[Zoophilia|illustrations of zoophilia]], and photos from [[hardcore pornography|hardcore pornographic]] films in its articles. It also has non-sexual [[Child nudity|photographs of nude children]].

The Wikipedia article about ''[[Virgin Killer]]—''a 1976 album from [[music of Germany|German]] [[heavy metal music|heavy metal]] [[rock band|band]] [[Scorpions (band)|Scorpions]]—features a picture of the album's original cover, which depicts a naked [[prepubescent]] girl. The original release cover caused controversy and was replaced in some countries. In December 2008, access to the Wikipedia article ''Virgin Killer'' was blocked for four days by most [[Internet service provider]]s in the United Kingdom after the [[Internet Watch Foundation]] (IWF) decided the album cover was a potentially illegal indecent image and added the article's URL to a "blacklist" it supplies to British internet service providers.<ref name="Register ISP censorship">{{cite news |title = Brit ISPs censor Wikipedia over 'child porn' album cover |first = Cade |last = Metz |work = [[The Register]] |date = December 7, 2008 |url = https://www.theregister.co.uk/2008/12/07/brit_isps_censor_wikipedia |accessdate = May 10, 2009 }}</ref>

In April 2010, Sanger wrote a letter to the Federal Bureau of Investigation, outlining his concerns that two categories of images on [[Wikimedia Commons]] contained child pornography, and were in violation of [[United States obscenity law|US federal obscenity law]].<ref>{{Cite news |url = http://www.smh.com.au/technology/technology-news/wikipedia-rejects-child-porn-accusation-20100428-tsvh |title = Wikipedia rejects child porn accusation |date = April 29, 2010 |work = The Sydney Morning Herald |access-date = May 14, 2017 |language = en-US |archive-url = https://web.archive.org/web/20170902180523/http://www.smh.com.au/technology/technology-news/wikipedia-rejects-child-porn-accusation-20100428-tsvh |archive-date = September 2, 2017 |dead-url = no |df = mdy-all }}</ref><ref name="Inquirer child abuse allegations">{{cite news |last = Farrell |first = Nick |title = Wikipedia denies child abuse allegations: Co-founder grassed the outfit to the FBI |newspaper = The Inquirer |date = April 29, 2010 |url = http://www.theinquirer.net/inquirer/news/1603521/wikipedia-denies-child-abuse-allegations |accessdate = October 9, 2010 }}</ref> Sanger later clarified that the images, which were related to [[pedophilia]] and one about [[lolicon]], were not of real children, but said that they constituted "obscene visual representations of the sexual abuse of children", under the [[Child pornography laws in the United States#Section 1466A|PROTECT Act of 2003]].<ref name="The Register-April" /> That law bans photographic child pornography and cartoon images and drawings of children that are [[Obscenity#United States obscenity law|obscene under American law]].<ref name="The Register-April" /> Sanger also expressed concerns about access to the images on Wikipedia in schools.<ref name="TET child porn accusations">{{cite news |title = Wikipedia blasts co-founder's accusations of child porn on website |date = April 29, 2010 |work = The Economic Times |location = India |url = http://economictimes.indiatimes.com/infotech/internet/Wikipedia-blasts-co-founders-accusations-of-child-porn-on-website/articleshow/5871943.cms |accessdate = April 29, 2010 }}</ref> [[Wikimedia Foundation]] spokesman Jay Walsh strongly rejected Sanger's accusation,<ref name="AFP" /> saying that Wikipedia did not have "material we would deem to be illegal. If we did, we would remove it."<ref name="AFP" /> Following the complaint by Sanger, Wales deleted sexual images without consulting the community. After some editors who volunteer to maintain the site argued that the decision to delete had been made hastily, Wales voluntarily gave up some of the powers he had held up to that time as part of his co-founder status. He wrote in a message to the Wikimedia Foundation mailing-list that this action was "in the interest of encouraging this discussion to be about real philosophical/content issues, rather than be about me and how quickly I acted".<ref name="BBC News Wales cedes rights">{{cite news |url = http://news.bbc.co.uk/2/hi/technology/10104946.stm |title = Wikimedia pornography row deepens as Wales cedes rights |publisher = BBC News |date = May 10, 2010 |accessdate = May 19, 2010 }}</ref> Critics, including [[Wikipediocracy]], noticed that many of the pornographic images deleted from Wikipedia since 2010 have reappeared.<ref name="XBIZ">{{cite news |url = http://newswire.xbiz.com/view.php?id=169017 |work = XBIZ.com |date = September 17, 2013 |first = Lila |last = Gray |title = Wikipedia Gives Porn a Break |accessdate = November 10, 2013 }}</ref>

=== Privacy ===

One [[privacy]] concern in the case of Wikipedia is the right of a private citizen to remain a "private citizen" rather than a "[[public figure]]" in the eyes of the law.<ref>Andrew McStay, 2014, [https://www.amazon.co.uk/Privacy-Philosophy-Affective-Protocol-Formations/dp/143311898X Privacy and Philosophy: New Media and Affective Protocol] {{webarchive |url=https://web.archive.org/web/20160414204326/http://www.amazon.co.uk/Privacy-Philosophy-Affective-Protocol-Formations/dp/143311898X |date=April 14, 2016 }}, New York Peter Lang.</ref><ref group=note>See [https://web.archive.org/web/20101130081035/http://texaspress.com/index.php/publications/law-media/731-law-a-the-media-in-texas--libel-cases "Libel"] by David McHam for the legal distinction.</ref> It is a battle between the right to be anonymous in [[cyberspace]] and the right to be anonymous in [[real life]] ("[[meatspace]]"). A particular problem occurs in the case of an individual who is relatively unimportant and for whom there exists a Wikipedia page against her or his wishes.

In January 2006, a German court ordered the [[German Wikipedia]] shut down within Germany because it stated the full name of [[Tron (hacker)|Boris Floricic]], aka "Tron", a deceased hacker. On February 9, 2006, the injunction against Wikimedia Deutschland was overturned, with the court rejecting the notion that Tron's [[right to privacy]] or that of his parents was being violated.<ref name="heise Tron public issue 1">[http://www.heise.de/newsticker/meldung/Gericht-weist-einstweilige-Verfuegung-gegen-Wikimedia-Deutschland-ab-Update-173587.html Heise] {{Webarchive|url=https://web.archive.org/web/20120913054949/http://www.heise.de/newsticker/meldung/Gericht-weist-einstweilige-Verfuegung-gegen-Wikimedia-Deutschland-ab-Update-173587.html |date=September 13, 2012 }} – {{lang|de|Gericht weist einstweilige Verfügung gegen Wikimedia Deutschland ab (update)}}, by Torsten Kleinz, February 9, 2006.</ref>

Wikipedia has a "{{visible anchor|Volunteer Response Team}}" that uses the [[OTRS]] system to handle queries without having to reveal the identities of the involved parties. This is used, for example, in confirming the permission for using individual images and other media in the project.<ref>{{cite web |title = IT Service Management Software |url = http://www.otrs.com/en/ |publisher = OTRS.com |accessdate = June 9, 2012 |deadurl = yes |archiveurl = https://web.archive.org/web/20131030215341/http://www.otrs.com/en/ |archivedate = October 30, 2013 |df = mdy-all }}</ref>

=== Sexism ===

{{main|Gender bias on Wikipedia}}

Wikipedia has been described as harboring a battleground culture of [[sexism]] and [[harassment]].<ref name="Paling">{{cite web |url = https://www.theatlantic.com/technology/archive/2015/10/how-wikipedia-is-hostile-to-women/411619/ |title = Wikipedia's Hostility to Women |last = Paling |first = Emma |date = October 21, 2015 |website = The Atlantic |access-date = October 24, 2015 }}</ref><ref>{{Cite journal |last1 = Auerbach |first1 = David |title = Encyclopedia Frown |url = http://www.slate.com/articles/technology/bitwise/2014/12/wikipedia_editing_disputes_the_crowdsourced_encyclopedia_has_become_a_rancorous.html |journal = Slate |accessdate = October 24, 2015 |date = December 11, 2014 }}</ref> The perceived toxic attitudes and tolerance of violent and abusive language are also reasons put forth for the gender gap in Wikipedia editors.<ref name="CSM-misogyny">{{Cite journal |url = http://www.csmonitor.com/World/Security-Watch/Backchannels/2013/0801/In-UK-rising-chorus-of-outrage-over-online-misogyny |title = In UK, rising chorus of outrage over online misogyny |journal = Christian Science Monitor |date = August 2013 }}</ref> In 2014, a female editor who requested a separate space on Wikipedia to discuss improving civility had her proposal referred to by a male editor using the words "the easiest way to avoid being called a [[cunt]] is not to act like one".{{r|Paling}}

== Operation ==

=== Wikimedia Foundation and Wikimedia movement affiliates ===

{{Main|Wikimedia Foundation}}

[[File:Katherine Maher.jpg|thumb|[[Katherine Maher]] is the third executive director at Wikimedia, following the departure of [[Lila Tretikov]] in 2016.|alt=Katherine Maher in 2016. She is seen with light skin, blonde hair, and blue eyes. She is seen wearing a black shirt.]]

Wikipedia is hosted and funded by the [[Wikimedia Foundation]], a non-profit organization which also operates Wikipedia-related projects such as [[Wiktionary]] and [[Wikibooks]]. The foundation relies on public contributions and grants to fund its mission.<ref name="financialstatements">{{cite web |url = http://upload.wikimedia.org/wikipedia/foundation/a/ac/FINAL_10_11From_KPMG.pdf |title = Wikimedia Foundation – Financial Statements – June 30, 2011 and 2010 |publisher = Wikimedia Foundation |accessdate = June 5, 2016 }}</ref> The foundation's 2013 IRS Form 990 shows revenue of $39.7 million and expenses of almost $29 million, with assets of $37.2 million and liabilities of about $2.3 million.<ref>{{cite web |url = http://upload.wikimedia.org/wikipedia/foundation/5/5c/Form_990_-_FY_12-13_-_Public.pdf |title = Wikimedia Foundation IRS Form 990 |accessdate = October 14, 2014 }}</ref>

In May 2014, Wikimedia Foundation named [[Lila Tretikov]] as its second executive director, taking over for Sue Gardner.<ref>{{cite web |url = https://wikimediafoundation.org/wiki/Press_releases/WMF_announces_new_ED_Lila_Tretikov |title = Press releases/WMF announces new ED Lila Tretikov |publisher = Wikimedia Foundation |date = May 31, 2018|accessdate = June 14, 2014 }}</ref> The ''Wall Street Journal'' reported on May 1, 2014, that Tretikov's information technology background from her years at University of California offers Wikipedia an opportunity to develop in more concentrated directions guided by her often repeated position statement that, "Information, like air, wants to be free."<ref name="Jeff Elder 2014">Jeff Elder, ''The Wall Street Journal'', May 1, 2014, "Wikipedia's New Chief: From Soviet Union to World's Sixth-Largest Site".</ref><ref name="nytimes.com">{{cite news |url = https://www.nytimes.com/2014/05/02/business/media/open-source-software-specialist-selected-as-executive-director-of-wikipedia.html?_r=0 |title = Media: Open-Source Software Specialist Selected as Executive Director of Wikipedia |author = Noam Cohen |date = May 1, 2014 |work = The New York Times }}</ref> The same ''Wall Street Journal'' article reported these directions of development according to an interview with spokesman Jay Walsh of Wikimedia, who "said Tretikov would address that issue ([[Conflict-of-interest editing on Wikipedia|paid advocacy]]) as a priority. 'We are really pushing toward more transparency... We are reinforcing that paid advocacy is not welcome.' Initiatives to involve greater diversity of contributors, better mobile support of Wikipedia, new geo-location tools to find local content more easily, and more tools for users in the second and third world are also priorities, Walsh said."<ref name="Jeff Elder 2014" />

Following the departure of Tretikov from Wikipedia due to issues concerning the use of the "superprotection" feature which some language versions of Wikipedia have adopted, Katherine Maher became the third executive director the Wikimedia Foundation in June 2016.<ref>Dimitra Kessenides. Bloomberg News Weekly. December 26, 2016. "Is Wikipedia 'Woke'".</ref> Maher has stated that one of her priorities would be the issue of editor harassment endemic to Wikipedia as identified by the Wikipedia board in December. Maher stated regarding the harassment issue that: "It establishes a sense within the community that this is a priority... (and that correction requires that) it has to be more than words."<ref>Dimitra Kessenides. Bloomberg News Weekly. December 26, 2016, p. 74. "Is Wikipedia 'Woke'".</ref>

Wikipedia is also supported by many organizations and groups that are affiliated with the Wikimedia Foundation but independently run, called [[Wikimedia movement affiliates]]. These include [[List of Wikimedia chapters|Wikimedia chapters]] (which are national or sub-national organizations, such as Wikimedia Deutschland and Wikimédia France), thematic organizations (such as Amical Wikimedia for the [[Catalan language]] community), and user groups. These affiliates participate in the promotion, development, and funding of Wikipedia.

=== Software operations and support ===

{{See also|MediaWiki}}

The operation of Wikipedia depends on [[MediaWiki]], a custom-made, [[free software|free]] and [[open source software|open source]] [[wiki software]] platform written in [[PHP]] and built upon the [[MySQL]] database system.<ref name="nedworks database system">{{cite web |url = http://www.nedworks.org/~mark/presentations/san/Wikimedia%20architecture.pdf |title = Wikimedia Architecture |author = Mark Bergsma |publisher = Wikimedia Foundation |accessdate = June 27, 2008 |archive-url = https://web.archive.org/web/20090303204708/http://www.nedworks.org/~mark/presentations/san/Wikimedia%20architecture.pdf |archive-date = March 3, 2009 }}</ref> The software incorporates programming features such as a [[Macro (computer science)|macro language]], [[variable (programming)|variables]], a [[transclusion]] system for [[Web template|templates]], and [[URL redirection]]. MediaWiki is licensed under the [[GNU General Public License]] and it is used by all Wikimedia projects, as well as many other wiki projects. Originally, Wikipedia ran on [[UseModWiki]] written in [[Perl]] by Clifford Adams (Phase I), which initially required [[CamelCase]] for article hyperlinks; the present double bracket style was incorporated later. Starting in January 2002 (Phase II), Wikipedia began running on a [[PhpWiki|PHP wiki]] engine with a MySQL database; this software was custom-made for Wikipedia by [[Magnus Manske]]. The Phase II software was repeatedly modified to accommodate the [[Exponential growth|exponentially increasing]] demand. In July 2002 (Phase III), Wikipedia shifted to the third-generation software, MediaWiki, originally written by [[Lee Daniel Crocker]].

Several MediaWiki extensions are installed<ref name="WP extensions installed">{{cite web |url = https://en.wikipedia.org/wiki/Special:Version |title = Version: Installed extensions |date = September 28, 2018 }}. Retrieved August 18, 2014.</ref> to extend the functionality of the MediaWiki software.

In April 2005, a [[Lucene]] extension<ref>{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Wikipedia_Signpost/2005-04-18/Lucene_search |title = Lucene search: Internal search function returns to service |publisher = Wikimedia Foundation |author = Michael Snow |accessdate = February 26, 2009 |date = December 29, 2016 }}</ref><ref>{{cite web |url = http://lists.wikimedia.org/pipermail/wikitech-l/2005-April/016297.html |title = [Wikitech-l&#93; Lucene search |author = Brion Vibber |accessdate = February 26, 2009 }}</ref> was added to MediaWiki's built-in search and Wikipedia switched from [[MySQL]] to Lucene for searching. The site currently uses Lucene Search 2.1,<ref>{{cite web |url = http://www.mediawiki.org/wiki/Extension:Lucene-search |title = Extension:Lucene-search |publisher = Wikimedia Foundation |accessdate = August 31, 2009 }}</ref>{{update inline|date=November 2016}} which is written in [[Java (programming language)|Java]] and based on Lucene library 2.3.<ref>{{cite web |url = https://phabricator.wikimedia.org/diffusion/SVN/browse/branches/lucene-search-2.1/lib/ |title = mediawiki&nbsp;– Revision 55688: /branches/lucene-search-2.1/lib |publisher = Wikimedia Foundation |accessdate = August 31, 2009 }}</ref>

In July 2013, after extensive beta testing, a WYSIWYG (What You See Is What You Get) extension, [[VisualEditor]], was opened to public use.<ref name="thenextwebve">{{cite web |website = The Next Web |url = https://thenextweb.com/insider/2013/07/02/wikimedia-rolls-out-its-wysiwyg-visual-editor-for-logged-in-users-accessing-wikipedia-articles-in-english/ |title = Wikimedia rolls out WYSIWYG visual editor for logged-in users accessing Wikipedia articles in English |author = Emil Protalinski |date = July 2, 2013 |accessdate = July 6, 2013 }}</ref><ref>{{Cite newspaper |url = https://www.telegraph.co.uk/technology/wikipedia/10196578/Wikipedia-introduces-new-features-to-entice-editors.html |publisher = The Daily Telegraph |title = Wikipedia introduces new features to entice editors |author = Curtis, Sophie |date = July 23, 2013 |accessdate = August 18, 2013 }}</ref><ref name="TheEconomistVE">{{cite news |work = [[The Economist]] |url = https://www.economist.com/blogs/babbage/2011/12/changes-wikipedia |title = Changes at Wikipedia: Seeing things |author = L. M. |date = December 13, 2011 |accessdate = July 28, 2013 }}</ref><ref name="softpedia-best">{{cite web |website = [[Softpedia]] |url = http://news.softpedia.com/news/Wikipedia-s-New-VisualEditor-Is-the-Best-Update-in-Years-and-You-Can-Make-It-Better-365072.shtml |title = Wikipedia's New VisualEditor Is the Best Update in Years and You Can Make It Better |author = Lucian Parfeni |date = July 2, 2013 |accessdate = July 30, 2013 }}</ref> It was met with much rejection and criticism, and was described as "slow and buggy".<ref name="Orlowski, Andrew">{{cite web |url = https://www.theregister.co.uk/2013/08/01/wikipedians_reject_wysiwyg_editor/ |title = Wikipedians say no to Jimmy's 'buggy' WYSIWYG editor |author = Orlowski, Andrew |date = August 1, 2013 |publisher = The Register |accessdate = August 18, 2013 }}</ref> The feature was changed from opt-out to opt-in afterward.

=== Automated editing ===

Computer programs called [[Internet bot|bots]] have often been used to perform simple and repetitive tasks, such as correcting common misspellings and stylistic issues, or to start articles such as geography entries in a standard format from statistical data.<ref>{{srlink|Wikipedia:Bots|Wikipedia Bot Information}}</ref><ref name="meetbots">{{cite news |title = Meet the 'bots' that edit Wikipedia |url = https://www.bbc.co.uk/news/magazine-18892510 |author = Daniel Nasaw |publisher = BBC News |date = July 24, 2012 }}</ref><ref>{{cite news |last = Halliday |first = Josh |author2 = Arthur, Charles |title = Boot up: The Wikipedia vandalism police, Apple analysts, and more |url = https://www.theguardian.com/technology/blog/2012/jul/26/boot-up-wikipedia-apple |newspaper = [[The Guardian]] |date = July 26, 2012 |accessdate = September 5, 2012 }}</ref> One controversial contributor creating articles with his bot was reported to create up to 10,000 articles on the Swedish Wikipedia on certain days.<ref>{{cite news|url=https://online.wsj.com/articles/for-this-author-10-000-wikipedia-articles-is-a-good-days-work-1405305001|title=For This Author, 10,000 Wikipedia Articles Is a Good Day's Work|last=Jervell|first=Ellen Emmerentze|date=July 13, 2014|work=The Wall Street Journal|accessdate=August 18, 2014}}</ref> Additionally, there are bots designed to automatically notify editors when they make common editing errors (such as unmatched quotes or unmatched parentheses).<ref>{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Wikipedia_Signpost/2009-03-23/Abuse_Filter |title = Wikipedia signpost: Abuse Filter is enabled |publisher = English Wikipedia |date = March 23, 2009 |accessdate = July 13, 2010 }}</ref><!--and prevent the creation of links to particular websites. Bots also find and revert changes by suspicious new accounts, enforce bans against shared [[IP address]]es or the use of [[Sockpuppet (Internet)|sockpuppets]] by a banned person operating from an alternate IP address.(unsourced/unverifiable)--> Edits falsely identified by bots as the work of a banned editor can be restored by other editors. [[User:ClueBot NG|An anti-vandal bot]] is programmed to detect and revert vandalism quickly.<ref name="meetbots" /> Bots are able to indicate edits from particular accounts or [[IP address]] ranges, as occurred at the time of the shooting down of the [[Malaysia Airlines Flight 17|MH17 jet]] incident in July 2014 when it was reported edits were made via IPs controlled by the Russian government.<ref>Aljazeera, July 21, 2014, "MH17 Wikipedia entry edited from Russian Government IP Address". {{cite web |url = http://stream.aljazeera.com/story/201407211855-0023944 |title = MH17 Wikipedia entry edited from Russian government IP address |accessdate = July 22, 2014 |deadurl = no |archiveurl = https://web.archive.org/web/20161116002928/http://stream.aljazeera.com/story/201407211855-0023944 |archivedate = November 16, 2016 |df = mdy |date = July 21, 2014 }}</ref> Bots on Wikipedia must be approved before activation.<ref>{{srlink|Wikipedia:Bot policy|Wikipedia's policy on bots}}</ref>

According to [[Andrew Lih]], the current expansion of Wikipedia to millions of articles would be difficult to envision without the use of such bots.<ref>Andrew Lih (2009). ''[[The Wikipedia Revolution]]'', chapter ''Then came the Bots'', pp. 99–106.</ref>

=== Hardware operations and support ===

{{See also|Wikimedia Foundation#Hardware}}

Wikipedia receives between 25,000 and 60,000 page requests per second, depending on time of day.<ref name="WP tools requests per day">[[tools:~leon/stats/reqstats/reqstats-monthly.png|"Monthly request statistics"]], Wikimedia. Retrieved October 31, 2008.</ref>{{Dead link|date=July 2015}}{{update inline|date=July 2019}} {{As of|2019||df=}}, page requests are first passed to a front-end layer of [[Varnish (software)|Varnish]] caching servers.<ref>{{Cite web|url=https://wikitech.wikimedia.org/wiki/Varnish|title=Varnish - Wikitech|website=wikitech.wikimedia.org|access-date=2019-05-12}}</ref> Further statistics, based on a publicly available 3-month Wikipedia access trace, are available.<ref name="globule access trace">{{cite web |url = http://www.globule.org/publi/WWADH_comnet2009.html |title = Wikipedia Workload Analysis for Decentralized Hosting |author = Guido Urdaneta, Guillaume Pierre and Maarten van Steen |publisher = Elsevier Computer Networks 53 (11), pp. 1830–1845, June 2009 |accessdate = June 5, 2016 }}</ref> Requests that cannot be served from the Varnish cache are sent to load-balancing servers running the [[Linux Virtual Server]] software, which in turn pass them to one of the Apache web servers for page rendering from the database. The web servers deliver pages as requested, performing page rendering for all the language editions of Wikipedia. To increase speed further, rendered pages are cached in a distributed memory cache until invalidated, allowing page rendering to be skipped entirely for most common page accesses.

[[File:Wikipedia webrequest flow 2015-10.png|alt=Diagram showing flow of data between Wikipedia's servers. Twenty database servers talk to hundreds of Apache servers in the backend; the Apache servers talk to fifty squids in the frontend.|center|thumb|Overview of system architecture {{As of|2015|10|lc=on|df=}}]]

Wikipedia currently runs on dedicated [[cluster (computing)|clusters]] of [[Linux]] servers (mainly [[Ubuntu (operating system)|Ubuntu]]).<ref name="CW WP simplifies infrastructure">{{cite news |title = Wikipedia simplifies IT infrastructure by moving to one Linux vendor |first = Todd R. |last = Weiss |newspaper = [[Computerworld]] |date = October 9, 2008 |url = http://www.computerworld.com/s/article/9116787/Wikipedia_simplifies_IT_infrastructure_by_moving_to_one_Linux_vendor?taxonomyId=154&pageNumber=1&taxonomyName=Servers%20and%20Data%20Center |accessdate = November 1, 2008 }}</ref><ref name="ars tech Ubuntu server infra">{{cite news |title = Wikipedia adopts Ubuntu for its server infrastructure |first = Ryan |last = Paul |url = https://arstechnica.com/open-source/news/2008/10/wikipedia-adopts-ubuntu-for-its-server-infrastructure.ars |publisher = Ars Technica |date = October 9, 2008 |accessdate = November 1, 2008 }}</ref> {{As of|2009|12}}, there were 300 in Florida and 44 in [[Amsterdam]].<ref name="servers" /> By January 22, 2013, Wikipedia had migrated its primary data center to an [[Equinix]] facility in [[Ashburn, Virginia]].<ref>{{cite web |url = https://blog.wikimedia.org/2013/01/19/wikimedia-sites-move-to-primary-data-center-in-ashburn-virginia/ |title = Wikimedia sites to move to primary data center in Ashburn, Virginia |first = Guillaume |last = Palmier |publisher = WMF |accessdate = June 5, 2016 }}</ref><ref>{{cite web |url = http://www.datacenterknowledge.com/archives/2013/01/14/its-official-equinix-ashburn-is-wikimedias-home/ |title = It's Official: Ashburn is Wikipedia's New Home |first = Jason |last = Verge |publisher = Data Center Knowledge |accessdate = June 5, 2016 |date = January 14, 2013 }}</ref> in 2017, Wikipedia had installed a caching cluster in an Equinix facility in [[Singapore]], the first of its kind in Asia.<ref>{{Cite web|url=https://phabricator.wikimedia.org/T156028|title=⚓ T156028 Name Asia Cache DC site|last=|first=|date=|website=Wikimedia Phabricator|archive-url=|archive-date=|dead-url=|access-date=2019-05-12}}</ref>

=== Internal research and operational development ===

In accordance with growing amounts of incoming donations exceeding seven digits in 2013 as recently reported,<ref name="Simonite-2013" /> the Foundation has reached a threshold of assets which qualify its consideration under the principles of [[industrial organization]] economics to indicate the need for the re-investment of donations into the internal research and development of the Foundation.<ref name=autogenerated5>Frederic M. Scherer and David Ross, [1970] 1990. ''Industrial Market Structure and Economic Performance'', 3rd ed. Houghton-Mifflin. {{SSRN|1496716}} and 1st ed. review [https://www.jstor.org/stable/3003013 extract].<br />&nbsp;&nbsp; • [[Google Scholar]] search of [https://archive.today/20120721074339/http://scholar.google.com/scholar?q=Frederic+M.+Scherer&hl=en&btnG=Search&as_sdt=1,47&as_sdtp=on Frederic M. Scherer]</ref> Two of the recent projects of such internal research and development have been the creation of a Visual Editor and a largely under-utilized "Thank" tab which were developed for the purpose of ameliorating issues of editor attrition, which have met with limited success.<ref name="Simonite-2013" /><ref name="Orlowski, Andrew" /> The estimates for reinvestment by industrial organizations into internal research and development was studied by Adam Jaffe, who recorded that the range of 4% to 25% annually was to be recommended, with high end technology requiring the higher level of support for internal reinvestment.<ref name="Patents, Citations pp 89-153">''Patents, Citations, and Innovations'', by Adam B. Jaffe, Manuel Trajtenberg, pp. 89–153.</ref> At the 2013 level of contributions for Wikimedia presently documented as 45 million dollars, the computed budget level recommended by Jaffe and Caballero for reinvestment into internal research and development is between 1.8 million and 11.3 million dollars annually.<ref name="Patents, Citations pp 89-153" /> In 2016, the level of contributions were reported by'' Bloomberg News'' as being at $77 million annually, updating the Jaffe estimates for the higher level of support to between $3.08 million and $19.2 million annually.<ref name="Patents, Citations pp 89-153" />

=== Internal news publications ===

Community-produced news publications include the [[English Wikipedia|English Wikipedia's]] [[WP:Signpost|''The Signpost'']], founded in 2005 by Michael Snow, an attorney, Wikipedia administrator and former chair of the [[Wikimedia Foundation]] board of trustees.<ref>{{cite news |url = https://www.nytimes.com/2007/03/05/technology/05wikipedia.html?pagewanted=2&_r=1 |title = A Contributor to Wikipedia Has His Fictional Side |first = Noam |last = Cohen |work = The New York Times |date = March 5, 2007 |accessdate = October 18, 2008 }}</ref> It covers news and events from the site, as well as major events from other [[Wikimedia project]]s, such as [[Wikimedia Commons]]. Similar publications are the German-language [[:de:WP:Kurier|''Kurier'']], and the Portuguese-language [[:pt:wp:Correio da Wikipédia|''Correio da Wikipédia'']]. Other past and present community news publications on English Wikipedia include the "Wikiworld" web comic, the [[WP:Wikipedia Weekly|''Wikipedia Weekly'']] podcast, and newsletters of specific WikiProjects like [[Wikipedia:BUGLE|''The Bugle'']] from [[WP:Milhist|WikiProject Military History]] and the monthly newsletter from [[WP:GOCE|The Guild of Copy Editors]]. There are also a number of publications from the Wikimedia Foundation and multilingual publications such as the [http://blog.wikimedia.org/ Wikimedia Blog] and ''[[:outreach:This Month in Education|This Month in Education]]''.

== Access to content ==

=== Content licensing ===

When the project was started in 2001, all text in Wikipedia was covered by the [[GNU Free Documentation License]] (GFDL), a [[copyleft]] license permitting the redistribution, creation of derivative works, and commercial use of content while authors retain copyright of their work.<ref name="WP copyright and commerciality 1">{{srlink|Wikipedia:Copyrights}}</ref> The GFDL was created for software manuals that come with [[free software]] programs licensed under the [[GPL]]. This made it a poor choice for a general reference work: for example, the GFDL requires the reprints of materials from Wikipedia to come with a full copy of the GFDL text. In December 2002, the [[Creative Commons license]] was released: it was specifically designed for creative works in general, not just for software manuals. The license gained popularity among bloggers and others distributing creative works on the Web. The Wikipedia project sought the switch to the Creative Commons.<ref name="WPF switch to CC">{{cite web |url = https://wikimediafoundation.org/wiki/Resolution:License_update |title = Resolution:License update |year = 2007 |author = Walter Vermeir |publisher = Wikizine |accessdate = December 4, 2007 }}</ref> Because the two licenses, GFDL and Creative Commons, were incompatible, in November 2008, following the request of the project, the [[Free Software Foundation]] (FSF) released a new version of the GFDL designed specifically to allow Wikipedia to {{srlink|Wikipedia:Licensing update|relicense its content to CC BY-SA}} by August 1, 2009. (A new version of the GFDL automatically covers Wikipedia contents.) In April 2009, Wikipedia and its sister projects held a community-wide referendum which decided the switch in June 2009.<ref name="voteresult" /><ref name="MW licensing QA">{{cite web |url = http://meta.wikimedia.org/wiki/Licensing_update/Questions_and_Answers |title = Licensing update/Questions and Answers |website = Wikimedia Meta |publisher = Wikimedia Foundation |accessdate = February 15, 2009 }}</ref><ref name="MW licensing timeline 1">{{cite web |url = http://meta.wikimedia.org/wiki/Licensing_update/Timeline |title = Licensing_update/Timeline |website = Wikimedia Meta |publisher = Wikimedia Foundation |accessdate = April 5, 2009 }}</ref><ref name="WP blog license migration">{{cite web |url = http://blog.wikimedia.org/2009/05/21/wikimedia-community-approves-license-migration |title = Wikimedia community approves license migration |website = Wikimedia Foundation |accessdate = May 21, 2009 }}</ref>

The handling of media files (e.g. image files) varies across language editions. Some language editions, such as the English Wikipedia, include non-free image files under [[fair use]] doctrine, while the others have opted not to, in part because of the lack of fair use doctrines in their home countries (e.g. in [[Copyright law of Japan|Japanese copyright law]]). Media files covered by [[free content]] licenses (e.g. [[Creative Commons]]' CC BY-SA) are shared across language editions via [[Wikimedia Commons]] repository, a project operated by the Wikimedia Foundation. Wikipedia's accommodation of varying international copyright laws regarding images has led some to observe that its photographic coverage of topics lags behind the quality of the encyclopedic text.<ref name="NYT photos on WP">{{cite news |url = https://www.nytimes.com/2009/07/20/arts/20funny.html |title = Wikipedia May Be a Font of Facts, but It's a Desert for Photos |date = July 19, 2009 |last = Cohen |first = Noam |publisher = New York Times |accessdate = March 9, 2013 }}</ref>

The Wikimedia Foundation is not a licensor of content, but merely a hosting service for the contributors (and licensors) of the Wikipedia. This position has been successfully defended in court.<ref name="reuters French defamation case">{{cite news |url = https://www.reuters.com/article/internetNews/idUSL0280486220071102?feedType=RSS&feedName=internetNews |title = Wikipedia cleared in French defamation case |agency = Reuters |date = November 2, 2007 |accessdate = November 2, 2007 }}</ref><ref name="ars tech WP dumb suing case">{{cite web |url = https://arstechnica.com/news.ars/post/20080502-dumb-idea-suing-wikipedia-for-calling-you-dumb.html |title = Dumb idea: suing Wikipedia for calling you "dumb" |first = Nate |last = Anderson |publisher = Ars Technica |date = May 2, 2008 |accessdate = May 4, 2008 }}</ref>

{{anchor|Reusing_Wikipedia.27s_content|Reusing_Wikipedia's_content}}Methods of access[edit | edit source]

Because Wikipedia content is distributed under an open license, anyone can reuse or re-distribute it at no charge. The content of Wikipedia has been published in many forms, both online and offline, outside of the Wikipedia website.

* '''Websites''' – Thousands of "[[mirror website|mirror sites]]" exist that republish content from Wikipedia: two prominent ones, that also include content from other reference sources, are [[Reference.com]] and [[Answers.com]]. Another example is [[Wapedia]], which began to display Wikipedia content in a mobile-device-friendly format before Wikipedia itself did.

* '''Mobile apps''' – A variety of mobile apps provide access to Wikipedia on [[hand-held device]]s, including both [[Android (operating system)|Android]] and [[iOS]] devices (see [[Wikipedia App|Wikipedia apps]]). (See also [[#Mobile access|Mobile access]].)

* '''Search engines''' – Some [[web search engine]]s make special use of Wikipedia content when displaying search results: examples include [[Bing (search engine)|Bing]] (via technology gained from [[Powerset (company)|Powerset]])<ref name="bing WP research and referencing" /> and [[DuckDuckGo]].

* '''Compact discs, DVDs''' – Collections of Wikipedia articles have been published on [[optical disc]]s. An English version, [[Wikipedia CD Selection|2006 Wikipedia CD Selection]], contained about 2,000 articles.<ref name="wikipediaondvd authorized 1">[http://www.wikipediaondvd.com/ "Wikipedia on DVD"] {{webarchive |url=https://web.archive.org/web/20130603205800/http://www.wikipediaondvd.com/ |date=June 3, 2013 }} Linterweb. Retrieved June 1, 2007. "Linterweb is authorized to make a commercial use of the Wikipedia trademark restricted to the selling of the Encyclopedia CDs and DVDs".</ref><ref name="wikipediaondvd commercially available 1">[http://www.wikipediaondvd.com/site.php?temp=buy "Wikipedia 0.5 Available on a CD-ROM"] {{webarchive |url=https://web.archive.org/web/20130503073535/http://www.wikipediaondvd.com/site.php?temp=buy |date=May 3, 2013 }} ''Wikipedia on DVD''. Linterweb. "The DVD or CD-ROM version 0.5 was commercially available for purchase." Retrieved June 1, 2007.</ref> The Polish-language version contains nearly 240,000 articles.<ref name="WM polish WP on dvd">{{cite web |url = http://meta.wikimedia.org/wiki/Polska_Wikipedia_na_DVD_%28z_Helionem%29/en |title = Polish Wikipedia on DVD |accessdate = December 26, 2008 }}</ref> There are German- and Spanish-language versions as well.<ref name="WP german on dvd 1">{{cite web |url = https://de.wikipedia.org/wiki/Wikipedia:DVD |title = Wikipedia:DVD |accessdate = December 26, 2008 |date = July 31, 2018 }}</ref><ref name="python.org CDPedia Argentina 1">{{cite web |url = http://python.org.ar/pyar/Proyectos/CDPedia |title = CDPedia (Python Argentina) |accessdate = July 7, 2011 }}</ref> Also, "Wikipedia for Schools", the Wikipedia series of CDs / DVDs produced by Wikipedians and [[SOS Children's Villages UK|SOS Children]], is a free, hand-checked, non-commercial selection from Wikipedia targeted around the [[National Curriculum (UK)|UK National Curriculum]] and intended to be useful for much of the English-speaking world.<ref name="WP CD selection 1" /> The project is available online; an equivalent print encyclopedia would require roughly 20 volumes.

* '''Printed books''' – There are efforts to put a select subset of Wikipedia's articles into printed book form.<ref name="WP into books 1">{{cite news |title = Wikipedia turned into book |url = https://www.telegraph.co.uk/news/newstopics/howaboutthat/5549589/Wikipedia-turned-into-book.html |archiveurl = https://www.webcitation.org/5jeCgQjpj?url=http://www.telegraph.co.uk/news/newstopics/howaboutthat/5549589/Wikipedia-turned-into-book.html |publisher = Telegraph Media Group |work = The Daily Telegraph |location = London |date = June 16, 2009 |accessdate = September 8, 2009 |archivedate = September 9, 2009 |deadurl = yes |df = mdy-all }}</ref><ref name="WP schools selection 1">{{cite web |url = http://schools-wikipedia.org |title = Wikipedia Selection for Schools |accessdate = July 14, 2012 |archive-url = https://web.archive.org/web/20120804093730/http://schools-wikipedia.org/ |archive-date = August 4, 2012 |dead-url = yes |df = mdy-all }}</ref> Since 2009, tens of thousands of [[print on demand|print-on-demand]] books that reproduced English, German, Russian and French Wikipedia articles have been produced by the American company [[Books LLC]] and by three [[Mauritius|Mauritian]] subsidiaries of the German publisher [[VDM Publishing|VDM]].<ref name="FAZ" />

* '''Semantic Web''' – The website [[DBpedia]], begun in 2007, extracts data from the infoboxes and category declarations of the English-language Wikipedia. Wikimedia has created the [[Wikidata]] project with a similar objective of storing the basic facts from each page of Wikipedia and the other WMF wikis and make it available in a queriable [[Semantic Web|semantic]] format, [[Resource Description Framework|RDF]]. This is still under development. As of February 2014 it has 15,000,000 items and 1,000 properties for describing them.

Obtaining the full contents of Wikipedia for reuse presents challenges, since direct cloning via a [[web crawler]] is discouraged.<ref name="WP DB usage policy 1" /> Wikipedia publishes [[Wikipedia:Database download|"dumps"]] of its contents, but these are text-only; {{as of|2007|lc=y}} there was no dump available of Wikipedia's images.<ref name="WP image data dumps 1">[[meta:Data dumps#Downloading Images|Data dumps: Downloading Images]], [[Wikimedia Meta-Wiki]]</ref>

Several languages of Wikipedia also maintain a [[WP:REFDESK|reference desk]], where volunteers answer questions from the general public. According to a study by Pnina Shachaf in the ''[[Journal of Documentation]]'', the quality of the Wikipedia reference desk is comparable to a standard [[library reference desk]], with an accuracy of 55 percent.<ref name="slis WP reference desk 1">{{cite web |url = http://www.slis.indiana.edu/news/story.php?story_id=2064 |title = Wikipedia Reference Desk |accessdate = September 9, 2014 }}</ref>

Mobile access{{anchor|Wikipedia mobile access|Wikipedia mobile}}[edit | edit source]

{{See also|Help:Mobile access}}

[[File:Wikipedia on Mobile screenshot 2019.png|thumb|The mobile version of the English Wikipedia's main page]]

Wikipedia's original medium was for users to read and edit content using any standard [[web browser]] through a fixed [[internet access|Internet connection]]. Although Wikipedia content has been accessible through the [[mobile web]] since July 2013, ''The New York Times'' on February 9, 2014, quoted Erik Möller, deputy director of the Wikimedia Foundation, stating that the transition of internet traffic from desktops to mobile devices was significant and a cause for concern and worry.<ref name="small screen" /> The article in ''The New York Times'' reported the comparison statistics for mobile edits stating that, "Only 20 percent of the readership of the English-language Wikipedia comes via mobile devices, a figure substantially lower than the percentage of mobile traffic for other media sites, many of which approach 50 percent. And the shift to mobile editing has lagged even more."<ref name="small screen" /> ''The New York Times'' reports that Möller has assigned "a team of 10 software developers focused on mobile", out of a total of approximately 200 employees working at the Wikimedia Foundation. One principal concern cited by ''The New York Times'' for the "worry" is for Wikipedia to effectively address attrition issues with the number of editors which the online encyclopedia attracts to edit and maintain its content in a mobile access environment.<ref name="small screen" />

''[[Bloomberg Businessweek]]'' reported in July 2014 that Google's Android mobile apps have dominated the largest share of global smartphone shipments for 2013 with 78.6% of market share over their next closest competitor in iOS with 15.2% of the market.<ref>Brad Stone, "How Google's Android chief, Sundar Pichai, became the most powerful man in mobile", June 30 – July 6, 2014, ''Bloomberg BusinessWeek'', pp. 47–51.</ref> At the time of the Tretikov appointment and her posted web interview with [[Sue Gardner]] in May 2014, Wikimedia representatives made a technical announcement concerning the number of mobile access systems in the market seeking access to Wikipedia. Directly after the posted web interview, the representatives stated that Wikimedia would be applying an all-inclusive approach to accommodate as many mobile access systems as possible in its efforts for expanding general mobile access, including BlackBerry and the Windows Phone system, making market share a secondary issue.<ref name="nytimes.com" /> The latest version of the Android app for Wikipedia was released on July 23, 2014, to generally positive reviews, scoring over four of a possible five in a poll of approximately 200,000 users downloading from Google.<ref>{{cite web |url = https://play.google.com/store/apps/details?id=org.wikipedia&hl=en |title = Wikipedia – Android Apps on Google Play |website = Play.Google.com |accessdate = August 21, 2014 }}</ref> The latest version for iOS was released on April 3, 2013, to similar reviews.<ref>{{cite web |url = https://itunes.apple.com/us/app/wikipedia-mobile/id324715238?mt=8 |title = Wikipedia Mobile on the App Store on iTunes |website = iTunes.Apple.com |date = August 4, 2014 |accessdate = August 21, 2014 }}</ref>

Access to Wikipedia from mobile phones was possible as early as 2004, through the [[Wireless Application Protocol]] (WAP), via the [[Wapedia]] service. In June 2007 Wikipedia launched [https://web.archive.org/web/20090112031222/http://en.mobile.wikipedia.org/ en.mobile.wikipedia.org], an official website for wireless devices. In 2009 a newer mobile service was officially released,<ref name="WM mobile added 1">{{cite web |title = Wikimedia Mobile is Officially Launched |website = Wikimedia Technical Blog |url = http://techblog.wikimedia.org/2009/06/wikimedia-mobile-launch |date = June 30, 2009 |accessdate = July 22, 2009 }}</ref> located at [https://en.m.wikipedia.org/ en.m.wikipedia.org], which caters to more advanced mobile devices such as the [[iPhone]], [[Android (operating system)|Android]]-based devices or [[WebOS]]-based devices. Several other methods of mobile access to Wikipedia have emerged. Many devices and applications optimize or enhance the display of Wikipedia content for mobile devices, while some also incorporate additional features such as use of Wikipedia [[metadata]] (See {{srlink|Wikipedia:Metadata}}), such as [[geoinformation]].<ref name="androgeoid.com LPOI WP 1">{{cite web |url = http://androgeoid.com/2011/04/local-points-of-interest-in-wikipedia |title = Local Points Of Interest In Wikipedia |date = May 15, 2011 |accessdate = May 15, 2011 }}</ref><ref name="ilounge iphone gems WP">{{cite web |url = http://www.ilounge.com/index.php/articles/comments/15802 |title = iPhone Gems: Wikipedia Apps |date = November 30, 2008 |accessdate = July 22, 2008 }}</ref>

[[Wikipedia Zero]] was an initiative of the Wikimedia Foundation to expand the reach of the encyclopedia to the developing countries.<ref>{{cite web |last = Ellis |first = Justin |url = http://www.niemanlab.org/2013/01/wikipedia-plans-to-expand-mobile-access-around-the-globe-with-new-funding |title = Wikipedia plans to expand mobile access around the globe with new funding |publisher = Nieman Journalism Lab |website = NiemanLab |date = January 17, 2013 |accessdate = April 22, 2013 }}</ref> It was discontinued in February 2018.<ref>{{Cite web|url=https://blog.wikimedia.org/2018/02/16/partnerships-new-approach/|title=Building for the future of Wikimedia with a new approach to partnerships – Wikimedia Blog|last=|first=|date=|website=[[Wikimedia Foundation]]|language=en|archive-url=|archive-date=|dead-url=|access-date=2019-05-12}}</ref>

[[Andrew Lih]] and [[Andrew Brown (writer)|Andrew Brown]] both maintain editing Wikipedia with [[smart phone]]s is difficult and this discourages new potential contributors. Several years running the number of Wikipedia editors has been falling and Tom Simonite of ''[[MIT Technology Review]]'' claims the bureaucratic structure and rules are a factor in this. Simonite alleges some [[Wikipedian]]s use the labyrinthine rules and guidelines to dominate others and those editors have a vested interest in keeping the [[status quo]].<ref name="Simonite-2013" /> Lih alleges there is serious disagreement among existing contributors how to resolve this. Lih fears for Wikipedia's long term future while Brown fears problems with Wikipedia will remain and rival encyclopedias will not replace it.<ref>{{cite news |url = https://www.nytimes.com/2015/06/21/opinion/can-wikipedia-survive.html |title = Can Wikipedia Survive? |author = Andrew Lih |date = June 20, 2015 }}</ref><ref>{{Cite newspaper |url = https://www.theguardian.com/commentisfree/2015/jun/25/wikipedia-editors-dying-breed-mobile-smartphone-technology-online-encyclopedia |title = Wikipedia editors are a dying breed. The reason? Mobile |author = Andrew Brown |journal = The Guardian |date = June 25, 2015 }}</ref>

Cultural impact{{anchor|Impact}}[edit | edit source]

=== Trusted source to combat fake news ===

In 2017–18, after a barrage of false news reports, both Facebook and YouTube announced they would rely on Wikipedia to help their users evaluate reports and reject false news. [[Noam Cohen]], writing in ''The Washington Post'' states, "YouTube’s reliance on Wikipedia to set the record straight builds on the thinking of another fact-challenged platform, the Facebook social network, which announced last year that Wikipedia would help its users root out 'fake news'."<ref name="auto"/> In answer to the question of 'how engaged are visitors to the site?' Alexa records the daily pageviews per visitor as 3.10 and the daily time on site as 4.11 minutes.<ref>Alexa.com. "Site Info". https://www.alexa.com/siteinfo/wikipedia.org Retrieved December 22, 2018.</ref>

=== Readership ===

In February 2014, ''The New York Times'' reported that Wikipedia is ranked fifth globally among all websites, stating "With 18 billion page views and nearly 500 million unique visitors a month [...] Wikipedia trails just Yahoo, Facebook, Microsoft and Google, the largest with 1.2 billion unique visitors."<ref name="small screen" />

In addition to [[Logistic function|logistic growth]] in the number of its articles,<ref name="modelling" /> Wikipedia has steadily gained status as a general reference website since its inception in 2001.<ref name="comscore" /> About 50 percent of search engine traffic to Wikipedia comes from Google,<ref name="hitwisegoogle" /> a good portion of which is related to academic research.<ref name="hitwiseAcademic" /> The number of readers of Wikipedia worldwide reached 365 million at the end of 2009.<ref name="365M" /> The [[Pew Research Center|Pew]] Internet and American Life project found that one third of US Internet users consulted Wikipedia.<ref name="Wikipedia users" /> In 2011 ''Business Insider'' gave Wikipedia a valuation of $4 billion if it ran advertisements.<ref>{{cite web |author = SAI |url = http://www.businessinsider.com/2011-digital-100#7-wikimedia-foundation-wikipedia-7 |title = The World's Most Valuable Startups |publisher = Business Insider |date = October 7, 2011 |accessdate = June 14, 2014 }}</ref>

According to "Wikipedia Readership Survey 2011", the average age of Wikipedia readers is 36, with a rough parity between genders. Almost half of Wikipedia readers visit the site more than five times a month, and a similar number of readers specifically look for Wikipedia in search engine results. About 47 percent of Wikipedia readers do not realize that Wikipedia is a non-profit organization.<ref>{{cite web |url = http://meta.wikimedia.org/wiki/Research:Wikipedia_Readership_Survey_2011/Results |title = Research:Wikipedia Readership Survey 2011/Results – Meta |publisher = Wikimedia |date = February 6, 2012 |accessdate = April 16, 2014 }}</ref>

=== Cultural significance ===

{{Main|Wikipedia in culture}}

[[File:Wikipedia Monument in Słubice - detail.JPG|thumb|''[[Wikipedia Monument]]'' in [[Słubice]], Poland]]

Wikipedia's content has also been used in academic studies, books, conferences, and court cases.<ref name="Wikipedia in media" /><ref name="Bourgeois" /><ref name="ssrn.com Wikipedian Justice 1">{{citation |ssrn = 1346311 |title = Wikipedian Justice |date = February 19, 2009 |last1 = Sharma |first1 = Raghav }}</ref> The [[Parliament of Canada]]'s website refers to Wikipedia's article on [[same-sex marriage]] in the "related links" section of its "further reading" list for the ''[[Civil Marriage Act]]''.<ref name="parl.gc.ca same-sex marriage">{{cite web |url = http://www.parl.gc.ca/LegisInfo/BillDetails.aspx?billId=1585203&View=10 |title = LEGISinfo – House Government Bill C-38 (38–1) |accessdate = September 9, 2014 }}</ref> The encyclopedia's assertions are increasingly used as a source by organizations such as the US federal courts and the [[World Intellectual Property Organization]]<ref name="WP_court_source" />—though mainly for ''supporting information'' rather than information decisive to a case.<ref name="Courts turn to Wikipedia" /> Content appearing on Wikipedia has also been cited as a source and referenced in some [[United States Intelligence Community|US intelligence agency]] reports.<ref name="US Intelligence" /> In December 2008, the scientific journal ''[[RNA Biology]]'' launched a new section for descriptions of families of RNA molecules and requires authors who contribute to the section to also submit a draft article on the [[Rfam|RNA family]] for publication in Wikipedia.<ref name="Declan" />

Wikipedia has also been used as a source in journalism,<ref name="ajr.org WP in the newsroom">{{cite news |title = Wikipedia in the Newsroom |url = http://www.ajr.org/Article.asp?id=4461 |date = February–March 2008 |work = American Journalism Review |first = Donna |last = Shaw |accessdate = February 11, 2008 }}</ref><ref name="twsY23" /> often without attribution, and several reporters have been dismissed for plagiarizing from Wikipedia.<ref name="shizuoka plagiarized WP 1">{{cite news |title = Shizuoka newspaper plagiarized Wikipedia article |work = Japan News Review |date = July 5, 2007 |url = http://www.japannewsreview.com/society/chubu/20070705page_id=364 |deadurl = yes |archiveurl = https://web.archive.org/web/20140312013353/http://www.japannewsreview.com/society/chubu/20070705page_id%3D364 |archivedate = March 12, 2014 |df = mdy-all }}</ref><ref name="WA Express-News staffer resigns">{{cite web |url = http://www.mysanantonio.com/news/metro/stories/MYSA010307.02A.richter.132c153.html |title = Express-News staffer resigns after plagiarism in column is discovered |accessdate = January 31, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20071015045010/http://www.mysanantonio.com/news/metro/stories/MYSA010307.02A.richter.132c153.html |archivedate = October 15, 2007 |df = }}, ''[[San Antonio Express-News]]'', January 9, 2007.</ref><ref name="starbulletin.com Inquiry prompts dismissal">{{cite web |url = http://archives.starbulletin.com/2006/01/13/news/story03.html |title = Inquiry prompts reporter's dismissal |website = Honolulu Star-Bulletin |author = Frank Bridgewater |accessdate = September 9, 2014 }}</ref>

In 2006, [[Time (magazine)|''Time'' magazine]] recognized Wikipedia's participation (along with YouTube, [[Reddit]], [[MySpace]], and Facebook<ref name="Time2006" />) in the rapid growth of online collaboration and interaction by millions of people worldwide.

In July 2007, Wikipedia was the focus of a 30-minute documentary on [[BBC Radio 4]]<ref>{{cite web |url = http://www.bbc.co.uk/programmes/b007tc6x |title = Radio 4 documentary, BBC |accessdate = April 24, 2016 |date = 2007 }}</ref> which argued that, with increased usage and awareness, the number of references to Wikipedia in popular culture is such that the word is one of a select band of 21st-century nouns that are so familiar ([[Google]], Facebook, YouTube) that they no longer need explanation.

On September 28, 2007, [[Italy|Italian]] politician [[Franco Grillini]] raised a parliamentary question with the minister of cultural resources and activities about the necessity of [[freedom of panorama]]. He said that the lack of such freedom forced Wikipedia, "the seventh most consulted website", to forbid all images of modern Italian buildings and art, and claimed this was hugely damaging to tourist revenues.<ref>{{cite web |url = http://www.grillini.it/show.php?4885 |title = Comunicato stampa. On. Franco Grillini. Wikipedia. Interrogazione a Rutelli. Con "diritto di panorama" promuovere arte e architettura contemporanea italiana. Rivedere con urgenza legge copyright |date = October 12, 2007 |language = Italian |trans-title = Press release. Honorable Franco Grillini. Wikipedia. Interview with Rutelli about the "right to view" promoting contemporary art and architecture of Italy. Review with urgency copyright law |accessdate = December 26, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20090330141810/http://www.grillini.it/show.php?4885 |archivedate = March 30, 2009 }}</ref>

[[File:Wikipedia, an introduction - Erasmus Prize 2015.webm|thumb|upright=1|thumbtime=00:36.00|Wikipedia, an introduction – [[Erasmus Prize]] 2015]]

[[File:Quadriga-verleihung-rr-02.jpg|thumb|upright=1|[[Jimmy Wales]] receiving the [[Quadriga (award)|Quadriga]] ''A Mission of Enlightenment'' award]]

On September 16, 2007, ''[[The Washington Post]]'' reported that Wikipedia had become a focal point in the [[2008 United States presidential election|2008 US election campaign]], saying: "Type a candidate's name into Google, and among the first results is a Wikipedia page, making those entries arguably as important as any ad in defining a candidate. Already, the presidential entries are being edited, dissected and debated countless times each day."<ref name="WP.com WP election usage">{{cite news |url = https://www.washingtonpost.com/wp-dyn/content/article/2007/09/16/AR2007091601699_pf.html |title = On Wikipedia, Debating 2008 Hopefuls' Every Facet |author = Jose Antonio Vargas |work = The Washington Post |date = September 17, 2007 |accessdate = December 26, 2008 }}</ref> An October 2007 [[Reuters]] article, titled "Wikipedia page the latest status symbol", reported the recent phenomenon of how having a Wikipedia article vindicates one's notability.<ref>{{cite news |url = https://www.reuters.com/article/domesticNews/idUSN2232893820071022?sp=true |title = Wikipedia page the latest status symbol |author = Jennifer Ablan |agency = Reuters |date = October 22, 2007 |accessdate = October 24, 2007 }}</ref>

Active participation also has an impact. Law students have been assigned to write Wikipedia articles as an exercise in clear and succinct writing for an uninitiated audience.<ref name="LER students write for WP 1">{{cite journal |title = Engaging with the World: Students of Comparative Law Write for Wikipedia |publisher = Legal Education Review |volume = 19 |issue = 1 and 2 |year = 2009 |pages = 83–98 |author = Witzleb, Normann }}</ref>

A working group led by [[Peter Stone (professor)|Peter Stone]] (formed as a part of the [[Stanford]]-based project ''[[One Hundred Year Study on Artificial Intelligence]]'') in its report called Wikipedia "the best-known example of crowdsourcing... that far exceeds traditionally-compiled information sources, such as encyclopedias and dictionaries, in scale and depth."<ref>{{cite web |url = https://ai100.stanford.edu/2016-report/section-i-what-artificial-intelligence/ai-research-trends |title = AI Research Trends |author = <!--Staff writer(s); no by-line.--> |date = |website = One Hundred Year Study on Artificial Intelligence (AI100) |publisher = Stanford University |access-date = September 3, 2016 |quote = }}</ref>

In a 2017 opinion piece for ''[[Wired (magazine)|Wired]]'', [[Hossein Derakhshan]] describes Wikipedia as "one of the last remaining pillars of the [[Openness|open]] and [[Decentralization#Centralization and redecentralization of the Internet|decentralized web]]" and contrasted its existence as a text-based source of knowledge with [[social media]] and [[social networking service]]s, the latter having "since colonized the web for television's values." For Derakhshan, Wikipedia's goal as an encyclopedia represents the [[Age of Enlightenment]] tradition of [[rationality]] triumphing over emotions, a trend which he considers "endangered" due to the "gradual shift from a [[typographic]] culture to a photographic one, which in turn mean[s] a shift from rationality to emotions, exposition to entertainment." Rather than "{{lang|la|[[sapere aude]]}}" ({{literal translation|'dare to know'|lk=on}}), social networks have led to a culture of "[d]are not to care to know." This is while Wikipedia faces "a more concerning problem" than funding, namely "a flattening growth rate in the number of contributors to the website." Consequently, the challenge for Wikipedia and those who use it is to "save Wikipedia and its promise of a free and open collection of all human knowledge amid the conquest of new and old television—how to collect and preserve knowledge when nobody cares to know."<ref>{{Cite news|last=Derakhshan|first=Hossein|author-link=Hossein Derakhshan|date=October 19, 2017|title=How Social Media Endangers Knowledge|url=https://www.wired.com/story/wikipedias-fate-shows-how-the-web-endangers-knowledge/|dead-url=no|department=Business|work=[[Wired (magazine)|Wired]]|publisher=[[Condé Nast]]|eissn=1078-3148|issn=1059-1028|archive-url=https://web.archive.org/web/20181022190537/https://www.wired.com/story/wikipedias-fate-shows-how-the-web-endangers-knowledge/|archive-date=October 22, 2018|access-date=October 22, 2018}}</ref>

==== Awards ====

[[File:Wikipedia team visiting to Parliament of Oviedo Spain 2015.JPG|thumb|upright=1|Wikipedia team visiting to Parliament of Asturias]]

[[File:Spanish Wikipedians meetup.jpg|thumb|upright=1|Wikipedians meeting after the Asturias awards ceremony]]

Wikipedia won two major awards in May 2004.<ref name="WP awards for WP 1">[[m:Trophy box|"Trophy box"]], {{srlink|Wikipedia:Meta|Meta-Wiki}} (March 28, 2005).</ref> The first was a Golden Nica for Digital Communities of the annual [[Prix Ars Electronica]] contest; this came with a €10,000 (£6,588; $12,700) grant and an invitation to present at the PAE Cyberarts Festival in [[Austria]] later that year. The second was a Judges' [[Webby Award]] for the "community" category.<ref name="webbyawards WP awards 1">{{cite web |url = http://www.webbyawards.com/webbys/winners-2004.php |title = Webby Awards 2004 |publisher = The International Academy of Digital Arts and Sciences |year = 2004 |archiveurl = https://web.archive.org/web/20110722174246/http://www.webbyawards.com/webbys/winners-2004.php |archivedate = July 22, 2011 }}</ref> Wikipedia was also nominated for a "Best Practices" Webby award.

In 2007, readers of brandchannel.com voted Wikipedia as the fourth-highest brand ranking, receiving 15 percent of the votes in answer to the question "Which brand had the most impact on our lives in 2006?"<ref name="brandchannel.com awards 1">{{cite news |first = Anthony |last = Zumpano |title = Similar Search Results: Google Wins |url = http://www.brandchannel.com/features_effect.asp?pf_id=352 |publisher = Interbrand |date = January 29, 2007 |accessdate = January 28, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20070220095907/http://brandchannel.com/features_effect.asp?pf_id=352 |archivedate = February 20, 2007 }}</ref>

In September 2008, Wikipedia received [[Quadriga (award)|Quadriga]] ''A Mission of Enlightenment'' award of Werkstatt Deutschland along with [[Boris Tadić]], [[Eckart Höfling]], and [[Peter Gabriel]]. The award was presented to Wales by [[David Weinberger]].<ref name="loomarea.com WP award 1">{{cite web |url = http://loomarea.com/die_quadriga/e/index.php?title=Award_2008 |archive-url = https://web.archive.org/web/20080915140714/http://loomarea.com/die_quadriga/e/index.php?title=Award_2008 |dead-url = yes |archive-date = September 15, 2008 |title = Die Quadriga&nbsp;– Award 2008 |accessdate = December 26, 2008 }}</ref>

In 2015, Wikipedia was awarded both the annual [[Erasmus Prize]], which recognizes exceptional contributions to culture, society or social sciences,<ref name="EP2015">{{cite web |url = http://www.erasmusprijs.org/?lang=en&page=Erasmusprijs |title = Erasmus Prize – Praemium Erasmianum |publisher = Praemium Erasmianum Foundation |accessdate = January 15, 2015 }}</ref> and the [[Spain|Spanish]] [[Princess of Asturias Award]] on International Cooperation.<ref>{{cite web |url = http://www.fpa.es/es/premios-princesa-de-asturias/premiados/2015-wikipedia.html?especifica=0&idCategoria=0&anio=2015&especifica=0 |title = Premio Princesa de Asturias de Cooperación Internacional 2015 |publisher = Fundación Princesa de Asturias |accessdate = June 17, 2015 }}</ref> Speaking at the Asturian Parliament in Oviedo, the city that hosts the awards ceremony, [[Jimmy Wales]] praised the work of the [[Asturian language]] Wikipedia users.<ref>{{cite web |title = Los fundadores de Wikipedia destacan la versión en asturiano |url = http://www.lne.es/sociedad-cultura/2015/10/22/fundadores-wikipedia-destacan-version-asturiano/1830529.html |publisher = La Nueva España |language = Spanish |trans-title = The founders of Wikipedia highlight the Asturian version |accessdate = October 20, 2015 }}</ref> The night of the ceremony, members of the Wikimedia Foundation held a meeting with Wikipedians from all parts of Spain, including the local [[Asturian Wikipedia|Asturian community]].

==== Satire ====

{{category see also|Parodies of Wikipedia}}

Many parodies target Wikipedia's openness and susceptibility to inserted inaccuracies, with characters vandalizing or modifying the online encyclopedia project's articles.

Comedian [[Stephen Colbert]] has parodied or referenced Wikipedia on numerous episodes of his show ''[[The Colbert Report]]'' and coined the related term ''[[wikiality]]'', meaning "together we can create a reality that we all agree on—the reality we just agreed on".<ref name="wikiality" /> Another example can be found in "Wikipedia Celebrates 750 Years of American Independence", a July 2006 front-page article in ''[[The Onion]]'',<ref name="onion WP 750 years 1">{{cite web |url = http://www.theonion.com/articles/wikipedia-celebrates-750-years-of-american-indepen,2007/ |title = Wikipedia Celebrates 750 Years Of American Independence |accessdate = October 15, 2006 |date = July 26, 2006 |website = [[The Onion]] }}</ref> as well as the 2010 ''The Onion'' article "'L.A. Law' Wikipedia Page Viewed 874 Times Today".<ref>{{cite web |url = http://www.theonion.com/articles/la-law-wikipedia-page-viewed-874-times-today,18521/ |title = 'L.A. Law' Wikipedia Page Viewed 874 Times Today |date = November 24, 2010 |website = [[The Onion]] }}</ref>

In an episode of the television comedy [[The Office (U.S. TV series)|''The Office'' U.S.]], which aired in April 2007, an incompetent office manager ([[Michael Scott (The Office)|Michael Scott]]) is shown relying on a hypothetical Wikipedia article for information on [[negotiation]] tactics in order to assist him in negotiating lesser pay for an employee.<ref>{{cite web |url = http://www.officetally.com/the-office-the-negotiation |title = The Office: The Negotiation, 3.19 |date = April 5, 2007 |accessdate = December 27, 2014 }}</ref> Viewers of the show tried to add the episode's mention of the page as a section of the actual Wikipedia article on negotiation, but this effort was prevented by other users on the article's talk page.<ref>{{cite web |url = http://usatoday30.usatoday.com/tech/webguide/internetlife/2007-04-12-office-wikipedia_N.htm |title = 'Office' fans, inspired by Michael Scott, flock to edit Wikipedia |publisher = USA Today |date = April 12, 2007 |accessdate = December 12, 2014 }}</ref>

"[[My Number One Doctor]]", a 2007 episode of the television show ''[[Scrubs (TV series)|Scrubs]]'', played on the perception that Wikipedia is an unreliable reference tool with a scene in which [[Perry Cox|Dr. Perry Cox]] reacts to a patient who says that a Wikipedia article indicates that the [[raw food diet]] reverses the effects of [[bone cancer]] by retorting that the same editor who wrote that article also wrote the [[List of Battlestar Galactica (2004 TV series) episodes|''Battlestar Galactica'' episode guide]].<ref name="Bakken one doctor 1">Bakken, Janae. "[[My Number One Doctor]]"; ''[[Scrubs (TV series)|Scrubs]]''; [[American Broadcasting Company|ABC]]; December 6, 2007.</ref>

In 2008, the comedic website ''[[CollegeHumor]]'' produced a video sketch named "Professor Wikipedia", in which the fictitious Professor Wikipedia instructs a class with a medley of unverifiable and occasionally absurd statements.<ref name="collegehumor.com WP funny 1">{{cite web |url = http://www.collegehumor.com/video/3581424/professor-wikipedia |title = Professor Wikipedia – CollegeHumor Video |publisher = CollegeHumor |date = November 17, 2009 |accessdate = April 19, 2011 }}</ref>

The ''[[Dilbert]]'' comic strip from May 8, 2009, features a character supporting an improbable claim by saying "Give me ten minutes and then check Wikipedia."<ref name="dilbert WP funny 1">{{cite web |url = http://dilbert.com/strips/comic/2009-05-08 |title = Dilbert comic strip for 05/08/2009 from the official Dilbert comic strips archive |publisher = Universal Uclick |date = May 8, 2009 |accessdate = March 10, 2013 }}</ref>

In July 2009, [[BBC Radio 4]] broadcast a comedy series called ''[[Bigipedia]]'', which was set on a website which was a parody of Wikipedia. Some of the sketches were directly inspired by Wikipedia and its articles.<ref name="comedy.org.uk WP funny 1">{{cite web |url = http://www.comedy.org.uk/guide/radio/bigipedia/interview/ |title = Interview With Nick Doody and Matt Kirshen |publisher = [[British Comedy Guide]] |accessdate = July 31, 2009 }}</ref>

In 2010, comedian Daniel Tosh encouraged viewers of his show, ''[[Tosh.0]]'', to visit the show's Wikipedia article and edit it at will. On a later episode, he commented on the edits to the article, most of them offensive, which had been made by the audience and had prompted the article to be locked from editing.<ref name="tosh CC WP funny 1">{{cite web |url = http://tosh.comedycentral.com/blog/2010/02/03/your-wikipedia-entries |title = Your Wikipedia Entries |date = February 3, 2010 |website = Tosh.0 |accessdate = September 9, 2014 }}</ref><ref name="tosh CC WP funny 2">{{cite web |url = http://tosh.comedycentral.com/video-clips/wikipedia-updates |title = Wikipedia Updates |date = February 3, 2010 |website = Tosh.0 |accessdate = September 9, 2014 }}</ref>

On August 23, 2013, the ''[[The New Yorker|New Yorker]]'' [[website]] published a cartoon with this caption: "Dammit, [[Chelsea Manning|Manning,]] have you considered the pronoun war that this is going to start on your Wikipedia page?"<ref>{{cite web |url = http://www.condenaststore.com/-sp/Dammit-Manning-have-you-considered-the-pronoun-war-that-this-is-going-t-Cartoon-Prints_i9813981_.htm |title = Manning/Wikipedia cartoon |accessdate = August 26, 2013 |author = Emily Flake |authorlink = Emily Flake |date = August 23, 2013 |deadurl = yes |archiveurl = https://web.archive.org/web/20141012052730/http://www.condenaststore.com/-sp/Dammit-Manning-have-you-considered-the-pronoun-war-that-this-is-going-t-Cartoon-Prints_i9813981_.htm |archivedate = October 12, 2014 |df = mdy-all }}</ref> The cartoon referred to Chelsea Elizabeth Manning (born Bradley Edward Manning), an American activist, politician, and former United States Army soldier and a trans woman.

In December 2015, [[John Julius Norwich]] stated, in a letter published in ''[[The Times]]'' newspaper, that as an historian he resorted to Wikipedia "at least a dozen times a day", and had never yet caught it out. He described it as "a work of reference as useful as any in existence", with so wide a range that it is almost impossible to find a person, place or thing that it has left uncovered, and that he could never have written his last two books without it.<ref>{{Cite newspaper |url = http://www.thetimes.co.uk/tto/opinion/letters/article4639755.ece |title = The obstacles to reforming our prisons – The Times |author = |date = December 14, 2015|journal = The Times |accessdate = June 5, 2016 }}</ref><ref>{{cite web |url = http://www.thetimes.co.uk/tto/public/sitesearch.do?querystring=john%20julius%20norwich&p=tto&pf=all&bl=on |title = john julius norwich -Search – The Times |author = |date = |website = thetimes.co.uk |accessdate = June 5, 2016 }}</ref>

=== Sister projects – Wikimedia ===

{{Main|Wikimedia project}}

Wikipedia has also spawned several sister projects, which are also wikis run by the [[Wikimedia Foundation]]. These other [[Wikimedia projects]] include [[Wiktionary]], a dictionary project launched in December 2002,<ref name="WM dictionary 1" /> [[Wikiquote]], a collection of quotations created a week after Wikimedia launched, [[Wikibooks]], a collection of collaboratively written free textbooks and annotated texts, [[Wikimedia Commons]], a site devoted to free-knowledge multimedia, [[Wikinews]], for citizen journalism, and [[Wikiversity]], a project for the creation of free learning materials and the provision of online learning activities.<ref name="OurProjects" /> Another sister project of Wikipedia, [[Wikispecies]], is a catalogue of species. In 2012 [[Wikivoyage]], an editable travel guide, and [[Wikidata]], an editable knowledge base, launched.

=== Publishing ===

[[File:WikiMedia DC 2013 Annual Meeting 08.JPG|right|thumb|A group of Wikimedians of the [http://wikimediadc.org/wiki/Home Wikimedia DC chapter] at the 2013 DC Wikimedia annual meeting standing in front of the ''Encyclopædia Britannica'' ''(back left)'' at the US National Archives]]

The most obvious economic effect of Wikipedia has been the death of commercial encyclopedias, especially the printed versions, e.g. ''[[Encyclopædia Britannica]],'' which were unable to compete with a product that is essentially free.<ref>{{cite web |last1 = Bosman |first1 = Julie |title = After 244 Years, Encyclopaedia Britannica Stops the Presses |url = http://mediadecoder.blogs.nytimes.com//2012/03/13/after-244-years-encyclopaedia-britannica-stops-the-presses/ |website = The New York Times |accessdate = January 26, 2015 |date = March 13, 2012 }}</ref><ref>{{cite web |url = http://www.gizmocrazed.com/2012/03/encyclopedia-britannica-dies-at-the-hands-of-wikipedia-infographic/ |title = ''Encyclopedia Britannica Dies At The Hands Of Wikipedia'', Gizmocrazed.com (with ''statista'' infographic from NYTimes.com) |publisher = Gizmocrazed.com |date = March 20, 2012 |accessdate = June 14, 2014 }}</ref><ref name="FT impact on traditional media">{{cite web |author = Christopher Caldwell (journalist) |authorlink = Christopher Caldwell (journalist) |date = June 14, 2013 |title = A chapter in the Enlightenment closes |url = http://www.ft.com/cms/s/0/ae22314a-d383-11e2-b3ff-00144feab7de.html |publisher = [[Financial Times|ft.com]] |accessdate = June 15, 2013 |quote = Bertelsmann did not resort to euphemism this week when it announced the end of the Brockhaus encyclopedia brand. Brockhaus had been publishing reference books for two centuries when the media group bought it in 2008. [...] The internet has finished off Brockhaus altogether. [...] What Germans like is Wikipedia. }}</ref> [[Nicholas G. Carr|Nicholas Carr]] wrote a 2005 essay, "The amorality of [[Web 2.0]]", that criticized websites with [[user-generated content]], like Wikipedia, for possibly leading to professional (and, in his view, superior) content producers' going out of business, because "free trumps quality all the time". Carr wrote: "Implicit in the ecstatic visions of Web 2.0 is the hegemony of the amateur. I for one can't imagine anything more frightening."<ref name="RType WP traditional media impact 1">{{cite web |title = The amorality of Web 2.0 |url = http://www.roughtype.com/archives/2005/10/the_amorality_o.php |date = October 3, 2005 |website = Rough Type |accessdate = July 15, 2006 }}</ref> Others dispute the notion that Wikipedia, or similar efforts, will entirely displace traditional publications. For instance, [[Chris Anderson (writer)|Chris Anderson]], the editor-in-chief of ''[[Wired (magazine)|Wired Magazine]]'', wrote in ''[[Nature (journal)|Nature]]'' that the "[[wisdom of crowds]]" approach of Wikipedia will not displace top [[scientific journal]]s, with their rigorous [[peer review]] process.<ref name="nature.com crowds wisdom" />

There is also an ongoing debate about the influence of Wikipedia on the biography publishing business. "The worry is that, if you can get all that information from Wikipedia, what's left for biography?" said [[Kathryn Hughes]], professor of life writing at UEA and author of ''The Short Life and Long Times of Mrs Beeton'' and ''George Eliot: the Last Victorian''.<ref>{{Cite newspaper |author = Alison Flood |url = https://www.theguardian.com/books/booksblog/2013/feb/07/traditional-biography-shakespeare-breakfast |title = Alison Flood: ''Should traditional biography be buried alongside Shakespeare's breakfast?'' |journal = The Guardian |date = February 7, 2013|accessdate = June 14, 2014 }}</ref>

=== Research use ===

Wikipedia has been widely used as a [[text corpus|corpus]] for linguistic research in [[computational linguistics]], [[information retrieval]] and [[natural language processing]]. In particular, it commonly serves as a target knowledge base for the [[entity linking]] problem, which is then called "wikification",<ref name="wikify">Rada Mihalcea and Andras Csomai (2007). [http://www.cse.unt.edu/~tarau/teaching/NLP/papers/Mihalcea-2007-Wikify-Linking_Documents_to_Encyclopedic.pdf Wikify! Linking Documents to Encyclopedic Knowledge] {{webarchive |url=https://web.archive.org/web/20160218062051/http://www.cse.unt.edu/~tarau/teaching/NLP/papers/Mihalcea-2007-Wikify-Linking_Documents_to_Encyclopedic.pdf |date=February 18, 2016 }} Proc. CIKM.</ref> and to the related problem of [[word sense disambiguation]].<ref name="milne witten WP usage 1">David Milne and Ian H. Witten (2008). Learning to link with Wikipedia. Proc. CIKM.</ref> Methods similar to wikification can in turn be used to find "missing" links in Wikipedia.<ref name="discovering missing WP links 1">Sisay Fissaha Adafre and [Maarten de Rijke] (2005). [http://staff.science.uva.nl/~mdr/Publications/Files/linkkdd2005.pdf Discovering missing links in Wikipedia] {{webarchive |url=https://web.archive.org/web/20120717054413/http://staff.science.uva.nl/~mdr/Publications/Files/linkkdd2005.pdf |date=July 17, 2012 }} Proc. LinkKDD.</ref>

In 2015, French researchers Dr José Lages of the [[University of Franche-Comté]] in [[Besançon]] and Dima Shepelyansky of [[Paul Sabatier University]] in [[Toulouse]] published a global university ranking based on Wikipedia scholarly citations.<ref name=mitmining>{{cite news |title = Wikipedia-Mining Algorithm Reveals World's Most Influential Universities: An algorithm's list of the most influential universities contains some surprising entries|url = http://www.technologyreview.com/view/544266/wikipedia-mining-algorithm-reveals-worlds-most-influential-universities/ |accessdate = December 27, 2015 |work = [[MIT Technology Review]] |date = December 7, 2015 }}</ref><ref name=harvardisonlymarmow>{{cite news |last1 = Marmow Shaw |first1 = Jessica |title = Harvard is only the 3rd most influential university in the world, according to this list |url = http://www.marketwatch.com/story/two-universities-beat-harvard-in-this-surprising-school-ranking-2015-12-09 |accessdate = December 27, 2015 |work = [[MarketWatch]] |date = December 10, 2015 }}</ref><ref name=wikipediarankingtimesworldunifranche>{{cite news |last1 = Bothwell |first1 = Ellie |title = Wikipedia Ranking of World Universities: the top 100. List ranks institutions by search engine results and Wikipedia appearances |url = https://www.timeshighereducation.com/features/wikipedia-ranking-world-universities-top-100 |accessdate = December 27, 2015 |work = [[Times Higher Education]] |date = December 15, 2015 }}</ref> They used [[PageRank]] "followed by the number of appearances in the 24 different language editions of Wikipedia (descending order) and the century in which they were founded (ascending order)."<ref name=wikipediarankingtimesworldunifranche />

A 2017 [[Massachusetts Institute of Technology|MIT]] study suggests that words used on Wikipedia articles end up in scientific publications.<ref>[https://www.sciencenews.org/blog/scicurious/wikipedia-science-reference-citations Wikipedia has become a science reference source even though scientists don’t cite it] {{Webarchive|url=https://web.archive.org/web/20180210120955/https://www.sciencenews.org/blog/scicurious/wikipedia-science-reference-citations |date=February 10, 2018 }} Science News, 2018</ref><ref>[https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3039505 Science Is Shaped by Wikipedia: Evidence from a Randomized Control Trial] {{Webarchive|url=https://web.archive.org/web/20171221090715/https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3039505 |date=December 21, 2017 }} SSRN, 2017</ref>

A 2018 [[Charles University]] study concluded that Wikipedia is the most used [[Open educational resources|OER]] for students of environmental studies (used by 95% of students) and argued that educational institutions should focus their attention on it (for example by supporting [[Wikipedian in residence|Wikipedians in residence)]].<ref>{{Cite journal|last=Petiška|first=Eduard|date=2018-12-10|title=Spíše Wikipedie než učebnice: Vzorce využívání otevřených vzdělávacích zdrojů studenty environmentálních oborů|url=https://envigogika.czp.cuni.cz/index.php/Envigogika/article/view/569|journal=Envigogika|language=cs|volume=13|issue=2|doi=10.14712/18023061.569|issn=1802-3061}}</ref> 

Studies related to Wikipedia has been using [[machine learning]] and [[artificial intelligence]] to support various operations. One of the most important areas—automatic detection of vandalism<ref>Sarabadani, A., Halfaker, A., & Taraborelli, D. (2017). [https://arxiv.org/pdf/1703.03861.pdf Building automated vandalism detection tools for Wikidata]. In Proceedings of the 26th International Conference on World Wide Web Companion (pp. 1647–1654). International World Wide Web Conferences Steering Committee.</ref><ref>Potthast, M., Stein, B., & Gerling, R. (2008). [https://pdfs.semanticscholar.org/8805/b4d923bee9c9534373425de81a1ba296d461.pdf Automatic vandalism detection in Wikipedia]. In European conference on information retrieval (pp. 663–668). Springer, Berlin, Heidelberg.</ref> and [[data quality]] assessment in Wikipedia,<ref>Asthana, S., & Halfaker, A. (2018). [https://dl.acm.org/ft_gateway.cfm?id=3274290&type=pdf With Few Eyes, All Hoaxes are Deep]. Proceedings of the ACM on Human-Computer Interaction, 2(CSCW), 21.</ref> which may include different measures for articles and infoboxes.<ref name="measures2019" />

== Related projects ==

A number of interactive multimedia encyclopedias incorporating entries written by the public existed long before Wikipedia was founded. The first of these was the 1986 [[BBC Domesday Project]], which included text (entered on [[BBC Micro]] computers) and photographs from over 1 million contributors in the UK, and covered the geography, art, and culture of the UK. This was the first interactive multimedia encyclopedia (and was also the first major multimedia document connected through internal links), with the majority of articles being accessible through an interactive map of the UK. The user interface and part of the content of the Domesday Project were emulated on a website until 2008.<ref name="Domesday Project" />

Several free-content, collaborative encyclopedias were created around the same period as Wikipedia (e.g. [[Everything2]]),<ref>{{cite news |url = http://www.cnn.com/2000/TECH/computing/11/21/net.gen.encyclopedias.idg/index.html |title = The next generation of online encyclopedias |last = Frauenfelder |first = Mark |website = CNN.com |publication-date = November 21, 2000 |archive-url = https://web.archive.org/web/20040814034109/http://www.cnn.com/2000/TECH/computing/11/21/net.gen.encyclopedias.idg/index.html |archive-date = August 14, 2004 |dead-url = yes }}</ref> with many later being merged into the project (e.g. [[GNE (encyclopedia)|GNE]]).<ref name="gnu.org">[https://www.gnu.org/encyclopedia/encyclopedia.html The Free Encyclopedia Project] gnu.org ( {{webarchive|url=https://www.webcitation.org/64QXgZhy2?url=http://www.gnu.org/encyclopedia/encyclopedia.html |date=January 3, 2012 }})</ref> One of the most successful early online encyclopedias incorporating entries by the public was [[h2g2]], which was created by [[Douglas Adams]] in 1999. The h2g2 encyclopedia is relatively light-hearted, focusing on articles which are both witty and informative.

Subsequent collaborative [[knowledge base|knowledge]] websites have drawn inspiration from Wikipedia. Some, such as [[Susning.nu]], [[Enciclopedia Libre Universal en Español|Enciclopedia Libre]], [[Hudong]], and [[Baidu Baike]] likewise employ no formal review process, although some like [[Conservapedia]] are not as open. Others use more traditional [[peer review]], such as [[Encyclopedia of Life]] and the online wiki encyclopedias ''[[Scholarpedia]]'' and [[Citizendium]]. The latter was started by Sanger in an attempt to create a reliable alternative to Wikipedia.<ref name="Orlowski18"/><ref name="JayLyman">{{cite news |first = Jay |last = Lyman |url = http://www.crmbuyer.com/story/53137.html |title = Wikipedia Co-Founder Planning New Expert-Authored Site |publisher = LinuxInsider |date = September 20, 2006 |accessdate = June 27, 2007 }}</ref>

== See also ==


{{Div col|colwidth=20em}}

* [[Conflict-of-interest editing on Wikipedia]]

* [[Democratization of knowledge]]

* [[Interpedia]], an early proposal for a collaborative [[Internet]] encyclopedia

* [[List of online encyclopedias]]

* [[List of Wikipedia controversies]]

* [[Network effect]]

* [[Outline of Wikipedia]]{{snd}}guide to the subject of ''Wikipedia'' presented as a [[tree structure]]d list of its subtopics; for an outline of the contents of ''Wikipedia'', see [[Portal:Contents/Outlines]]

* [[Print Wikipedia]] art project to visualize how big Wikipedia is. In cooperation with Wikimedia foundation.

  • [[QRpedia]]{{snd}}multilingual, mobile interface to Wikipedia

* [[Wikipedia Review]]

{{Div col end}}

== Notes ==


== References ==


<ref name="nature.com crowds wisdom">{{cite web |title = Technical solutions: Wisdom of the crowds |url = http://www.nature.com/nature/peerreview/debate/nature04992.html |website = Nature |accessdate = October 10, 2006 }}</ref>

<ref name=modelling>{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Modelling_Wikipedia%27s_growth |title = Wikipedia:Modelling Wikipedia's growth |accessdate = December 22, 2007 |date = July 31, 2018 }}</ref>

<ref name="Alexa siteinfo">{{cite web |title=Wikipedia.org Traffic, Demographics and Competitors |url=https://www.alexa.com/siteinfo/wikipedia.org |website=www.alexa.com |accessdate=October 9, 2018 |language=en}}</ref>

<ref name=comscore>{{cite web |url = http://www.comscore.com/press/release.asp?press=849 |title = 694 Million People Currently Use the Internet Worldwide According To comScore Networks |date = May 4, 2006 |publisher = comScore |accessdate = December 16, 2007 |quote = Wikipedia has emerged as a site that continues to increase in popularity, both globally and in the US |archiveurl = https://web.archive.org/web/20080730011713/http://www.comscore.com/press/release.asp?press=849 |archivedate = July 30, 2008 }}</ref>

<ref name=hitwisegoogle>{{cite web |url = http://weblogs.hitwise.com/leeann-prescott/2007/02/wikipedia_traffic_sources.html |title = Google Traffic To Wikipedia up 166% Year over Year |publisher = Hitwise |date = February 16, 2007 |accessdate = December 22, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20071214072031/http://weblogs.hitwise.com/leeann-prescott/2007/02/wikipedia_traffic_sources.html |archivedate = December 14, 2007 |df = mdy-all }}</ref>

<ref name=hitwiseAcademic>{{cite web |url = http://weblogs.hitwise.com/leeann-prescott/2006/10/wikipedia_and_academic_researc.html |title = Wikipedia and Academic Research |publisher = Hitwise |date = October 17, 2006 |accessdate = February 6, 2008 |deadurl = yes |archiveurl = https://web.archive.org/web/20061029213453/http://weblogs.hitwise.com/leeann-prescott/2006/10/wikipedia_and_academic_researc.html |archivedate = October 29, 2006 |df = mdy-all }}</ref>

<ref name="Wikipedia users">{{cite web |first = Lee |last = Rainie |author2 = Bill Tancer |title = Wikipedia users |publisher = Pew Research Center |website = Pew Internet & American Life Project |date = December 15, 2007 |quote = 36% of online American adults consult Wikipedia. It is particularly popular with the well-educated and current college-age students. |url = http://www.pewinternet.org/pdfs/PIP_Wikipedia07.pdf |accessdate = December 15, 2007 |archiveurl = https://web.archive.org/web/20080306031354/http://www.pewinternet.org/pdfs/PIP_Wikipedia07.pdf |archivedate = March 6, 2008 }}</ref>

<ref name="Wikipedia in media">{{cite web |url = https://en.wikipedia.org/wiki/Wikipedia:Wikipedia_in_the_media |title = Wikipedia:Wikipedia in the media |website = Wikipedia |accessdate = December 26, 2008 |date = July 4, 2018 }}</ref>

<ref name="Bourgeois">{{cite web |url = http://www.ca11.uscourts.gov/opinions/ops/200216886.pdf |title = Bourgeois ''et al.'' v. Peters ''et al.'' |accessdate = February 6, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20070203021430/http://www.ca11.uscourts.gov/opinions/ops/200216886.pdf |archivedate = February 3, 2007 }}</ref>

<ref name="Courts turn to Wikipedia">{{cite news |last = Cohen |first = Noam |date = January 29, 2007 |title = Courts Turn to Wikipedia, but Selectively |work = The New York Times |url = https://www.nytimes.com/2007/01/29/technology/29wikipedia.html |accessdate = December 26, 2008 }}</ref>

<ref name="US Intelligence">{{cite web |url = https://fas.org/blog/secrecy/2007/03/the_wikipedia_factor_in_us_int.html |title = The Wikipedia Factor in US Intelligence |first = Steven |last = Aftergood |publisher = Federation of American Scientists Project on Government Secrecy |date = March 21, 2007 |accessdate = April 14, 2007 }}</ref>

<ref name="Declan">{{cite journal |last = Butler |first = Declan |date = December 16, 2008 |title = Publish in Wikipedia or perish |journal = Nature News |doi = 10.1038/news.2008.1312 }}</ref>

<ref name="Sidener">{{Cite news |url = http://www.signonsandiego.com/uniontrib/20041206/news_mz1b6encyclo.html |title = Everyone's Encyclopedia |last = Sidener |first = Jonathan |work = [[U-T San Diego]] |publication-date = December 6, 2004 |archive-url = https://web.archive.org/web/20160114101809/http://www.sandiegouniontribune.com/uniontrib/20041206/news_mz1b6encyclo.html |archive-date = January 14, 2016 |dead-url = yes |access-date = October 15, 2006 }}</ref>

<ref name=MiliardWho>{{cite news |url = http://www.cityweekly.net/utah/article-5129-feature-wikipediots-who-are-these-devoted-even-obsessive-contributors-to-wikipedia.html |author = Mike Miliard |title = Wikipediots: Who Are These Devoted, Even Obsessive Contributors to Wikipedia? |work = [[Salt Lake City Weekly]] |date = March 1, 2008 |accessdate = December 18, 2008 }}</ref>

<ref name=Time2006>{{cite news |date = December 13, 2006 |url = http://content.time.com/time/magazine/article/0,9171,1570810,00.html |title = Time's Person of the Year: You |work = Time |publisher = |accessdate = December 26, 2008 |first = Lev |last = Grossman }}</ref>

<ref name="AcademiaAndWikipedia">{{cite web |author = Danah Boyd |url = http://many.corante.com/archives/2005/01/04/academia_and_wikipedia.php |archive-url = https://web.archive.org/web/20060316184224/http://many.corante.com/archives/2005/01/04/academia_and_wikipedia.php |dead-url = yes |archive-date = March 16, 2006 |title = Academia and Wikipedia |website = Many 2 Many: A Group [[Blog|Weblog]] on Social Software |publisher = Corante |date = January 4, 2005 |accessdate = December 18, 2008 |quote = [The author, Danah Boyd, describes herself as] an expert on social media[,] [...] a doctoral student in the School of Information at the [[University of California, Berkeley]] [,] and a fellow at the [[Harvard University]] [[Berkman Center for Internet & Society]] [at [[Harvard Law School]].] }}</ref>

<ref name="MIT_IBM_study">{{Cite book|author = Fernanda B. Viégas |author2 = Martin Wattenberg |author3 = Kushal Dave |url = http://alumni.media.mit.edu/~fviegas/papers/history_flow.pdf |archiveurl = https://web.archive.org/web/20060125025047/http://alumni.media.mit.edu/~fviegas/papers/history_flow.pdf |archivedate = January 25, 2006 |title = Studying Cooperation and Conflict between Authors with History Flow Visualizations |journal = Proceedings of the ACM Conference on Human Factors in Computing Systems (CHI) |pages = 575–582 |year = 2004 |doi = 10.1145/985921.985953 |isbn = 978-1-58113-702-6 |accessdate = January 24, 2007 }}</ref>

<ref name="CreatingDestroyingAndRestoringValue">{{cite journal |author = Reid Priedhorsky |author2 = Jilin Chen |author3 = Shyong (Tony) K. Lam |author4 = Katherine Panciera |author5 = Loren Terveen |author6 = John Riedl |title = Creating, Destroying, and Restoring Value in Wikipedia |journal = Association for Computing Machinery GROUP '07 Conference Proceedings; GroupLens Research, Department of Computer Science and Engineering, University of Minnesota |date = November 4, 2007 |url = http://www-users.cs.umn.edu/~reid/papers/group282-priedhorsky.pdf |accessdate = October 13, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20071025080718/http://www-users.cs.umn.edu/~reid/papers/group282-priedhorsky.pdf |archivedate = October 25, 2007 |df = mdy-all }}</ref>

<ref name="stallman1999">{{cite web |url = https://www.gnu.org/encyclopedia/encyclopedia.html |title = The Free Encyclopedia Project |author = Richard M. Stallman |authorlink = Richard Stallman |date = June 20, 2007 |publisher = Free Software Foundation |accessdate = January 4, 2008 }}</ref>

<ref name=autogenerated1>{{cite news |url = http://www.signonsandiego.com/uniontrib/20041206/news_mz1b6encyclo.html |author = Jonathan Sidener |title = Everyone's Encyclopedia |date = December 6, 2004 |work = [[U-T San Diego]] |accessdate = October 15, 2006 |deadurl = yes |archiveurl = https://web.archive.org/web/20071011150228/http://signonsandiego.com/uniontrib/20041206/news_mz1b6encyclo.html |archivedate = October 11, 2007 }}</ref>

<ref name=Meyers>{{cite news |first = Peter |last = Meyers |title = Fact-Driven? Collegial? This Site Wants You |url = https://www.nytimes.com/2001/09/20/technology/fact-driven-collegial-this-site-wants-you.html?n=Top%2FReference%2FTimes+Topics%2FSubjects%2FC%2FComputer+Software|work = The New York Times |date = September 20, 2001 |quote = 'I can start an article that will consist of one paragraph, and then a real expert will come along and add three paragraphs and clean up my one paragraph,' said Larry Sanger of Las Vegas, who founded Wikipedia with Mr. Wales. |accessdate = November 22, 2007 }}</ref>

<ref name=SangerMemoir>{{cite news |first = Larry |last = Sanger |title = The Early History of Nupedia and Wikipedia: A Memoir |date = April 18, 2005 |work = Slashdot |url = http://features.slashdot.org/features/05/04/18/164213.shtml |accessdate = December 26, 2008 }}</ref>

<ref name=Sanger>{{cite news |first = Larry |last = Sanger |title = Wikipedia Is Up! |date = January 17, 2001 |url = http://www.nupedia.com/pipermail/nupedia-l/2001-January/000684.html |accessdate = December 26, 2008 |archiveurl = https://web.archive.org/web/20010506042824/http://www.nupedia.com/pipermail/nupedia-l/2001-January/000684.html |archivedate = May 6, 2001 }}</ref>

<ref name=WikipediaHome>{{cite web |url = http://www.wikipedia.com/ |archiveurl = https://web.archive.org/web/20010331173908/http://www.wikipedia.com/ |archivedate = March 31, 2001 |title = Wikipedia: HomePage |accessdate = March 31, 2001 }}</ref>

<ref name="NPOV">"[[Wikipedia:Neutral point of view]], Wikipedia (January 21, 2007).</ref>

<ref name="EB_encyclopedia">{{cite encyclopedia |title = Encyclopedias and Dictionaries |encyclopedia = Encyclopædia Britannica |edition = 15th |year = 2007 |volume = 18 |pages = 257–286 |url = |author1 = <!-- Please add first missing authors to populate metadata.--> }}</ref>

<ref name=Shirky>{{cite book |author = Clay Shirky |authorlink = Clay Shirky |title = Here Comes Everybody: The Power of Organizing Without Organizations |date = February 28, 2008 |publisher = The Penguin Press via Amazon Online Reader |url = https://www.amazon.com/gp/reader/1594201536/ref=sib_dp_srch_pop?v=search-inside&keywords=spanish&go.x=0&go.y=0&go=Go%21 |isbn = 978-1-59420-153-0 |page = 273 |accessdate = December 26, 2008 }}</ref>

<ref name=NOR>{{srlink|Wikipedia:No original research|No original research}}. February 13, 2008. "Wikipedia does not publish original thought."</ref>

<ref name=autogenerated2>{{srlink|Wikipedia:Neutral point of view|Neutral point of view}}. February 13, 2008. "All Wikipedia articles and other encyclopedic content must be written from a neutral point of view, representing significant views fairly, proportionately and without bias."</ref>

<ref name="voteresult">[[meta:Licensing update/Result|Wikimedia]]</ref>

<ref name=FAZ>{{cite web |last = Thiel |first = Thomas |title = Wikipedia und Amazon: Der Marketplace soll es richten |website = Frankfurter Allgemeine Zeitung |publisher = [[Frankfurter Allgemeine Zeitung]] |language = German |date = September 27, 2010 |url = http://www.faz.net/s/RubCF3AEB154CE64960822FA5429A182360/Doc~E7A20980B9C0D46E99A9F60BC09506343~ATpl~Ecommon~Scontent.html |accessdate = December 6, 2010 |deadurl = yes |archiveurl = https://web.archive.org/web/20101126184904/http://www.faz.net/s/RubCF3AEB154CE64960822FA5429A182360/Doc~E7A20980B9C0D46E99A9F60BC09506343~ATpl~Ecommon~Scontent.html |archivedate = November 26, 2010 }}</ref>

<ref name="Seigenthaler">{{cite news |url = https://www.usatoday.com/news/opinion/editorials/2005-11-29-wikipedia-edit_x.htm |last = Seigenthaler |first = John |title = A False Wikipedia 'biography' |date = November 29, 2005 |work = USA Today |accessdate = December 26, 2008 }}</ref>

<ref name="Torsten_Kleinz">{{cite news |first = Torsten |last = Kleinz |title = World of Knowledge |work = Linux Magazine |quote = The Wikipedia's open structure makes it a target for trolls and vandals who malevolently add incorrect information to articles, get other people tied up in endless discussions, and generally do everything to draw attention to themselves. |date = February 2005 |url = http://w3.linux-magazine.com/issue/51/Wikipedia_Encyclopedia.pdf |format = PDF |accessdate = July 13, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20070925220722/http://w3.linux-magazine.com/issue/51/Wikipedia_Encyclopedia.pdf |archivedate = September 25, 2007 |df = mdy-all }}</ref>

<ref name="DeathByWikipedia">{{cite news |title = Death by Wikipedia: The Kenneth Lay Chronicles |url = https://www.washingtonpost.com/wp-dyn/content/article/2006/07/08/AR2006070800135.html |first = Frank |last = Ahrens |work = The Washington Post |date = July 9, 2006 |accessdate = November 1, 2006 }}</ref>

<ref name="wikiality">{{cite news |title = Wikiality |url = http://www.cc.com/video-clips/z1aahs/the-colbert-report-the-word---wikiality |author = Stephen Colbert |date = July 30, 2006 |accessdate = October 8, 2015 }}</ref>

<ref name="Seeing Corporate Fingerprints">{{cite news |url = https://www.nytimes.com/2007/08/19/technology/19wikipedia.html |title = Lifting Corporate Fingerprints From the Editing of Wikipedia |first = Katie |last = Hafner |work = The New York Times |date = August 19, 2007 |accessdate = December 26, 2008 |page = 1 }}</ref>

<ref name=Taylor>{{cite news |url = http://in.reuters.com/article/technologyNews/idINIndia-32865420080405 |title = China allows access to English Wikipedia |agency = Reuters |author = Sophie Taylor |date = April 5, 2008 |accessdate = July 29, 2008 }}</ref>

<ref name=Kittur2009>Kittur, A., Chi, E. H., and Suh, B. 2009. [http://www-users.cs.umn.edu/~echi/papers/2009-CHI2009/p1509.pdf What's in Wikipedia? Mapping Topics and Conflict Using Socially Annotated Category Structure] {{webarchive |url=https://web.archive.org/web/20160413130503/http://www-users.cs.umn.edu/~echi/papers/2009-CHI2009/p1509.pdf |date=April 13, 2016 }} In Proceedings of the 27th international Conference on Human Factors in Computing Systems (Boston, Massachusetts, April 4–9, 2009). CHI '09. ACM, New York, 1509–1512.</ref>

<ref name=Rosenzweig>{{cite journal |author = Roy Rosenzweig |title = Can History be Open Source? Wikipedia and the Future of the Past |journal = The Journal of American History |volume = 93 |issue = 1 |date = June 2006 |pages = 117–146 |url = http://chnm.gmu.edu/essays-on-history-new-media/essays/?essayid=42 |archive-url = https://web.archive.org/web/20100425130754/http://chnm.gmu.edu/essays-on-history-new-media/essays/?essayid=42 |dead-url = yes |archive-date = April 25, 2010 |accessdate = August 11, 2006 |doi = 10.2307/4486062 |jstor = 4486062 |df = }} (Center for History and New Media.)</ref>

<ref name="WikipediaWatch">Public Information Research, Wikipedia Watch</ref>

<ref name="McHenry_2004">[[Robert McHenry]], [https://web.archive.org/web/20060107210301/http://www.techcentralstation.com/111504A.html "The Faith-Based Encyclopedia"] {{webarchive |url=https://web.archive.org/web/20060116022451/http://www.techcentralstation.com/111504A.html |date=January 16, 2006 }}, [[TCS Daily|Tech Central Station]], November 15, 2004.</ref>

<ref name="WideWorldOfWikipedia">{{cite web |title = Wide World of Wikipedia |publisher = The Emory Wheel |url = http://www.emorywheel.com/detail.php?n=17902 |date = April 21, 2006 |accessdate = October 17, 2007 |deadurl = yes |archiveurl = https://web.archive.org/web/20071107052908/http://www.emorywheel.com/detail.php?n=17902 |archivedate = November 7, 2007 }}</ref>

<ref name="AWorkInProgress">{{cite news |first = Burt |last = Helm |title = Wikipedia: 'A Work in Progress' |url = http://www.businessweek.com/technology/content/dec2005/tc20051214_441708.htm |work = Bloomberg BusinessWeek |date = December 14, 2005 |accessdate = January 29, 2007 |archivedate = April 21, 2012 |deadurl = yes |archiveurl = https://web.archive.org/web/20120421000522/http://www.businessweek.com/technology/content/dec2005/tc20051214_441708.htm }}</ref>

<ref name="GilesJ2005Internet">{{cite journal |author = Jim Giles |title = Internet encyclopedias go head to head |journal = [[Nature (journal)|Nature]] |volume = 438 |issue = 7070 |pages = 900–901 |date = December 2005 |pmid = 16355180 |doi = 10.1038/438900a |authorlink = Jim Giles (reporter) |bibcode = 2005Natur.438..900G }}{{subscription required}}

Note: The study was cited in several news articles; e.g.:

  • {{cite news |title = Wikipedia survives research test |publisher = BBC News |url = http://news.bbc.co.uk/2/hi/technology/4530930.stm |date = December 15, 2005 |accessdate = }}</ref>

<ref name="corporate.britannica.com">[http://corporate.britannica.com/britannica_nature_response.pdf Fatally Flawed: Refuting the recent study on encyclopedic accuracy by the journal Nature] {{webarchive |url=https://web.archive.org/web/20160709053629/http://corporate.britannica.com/britannica_nature_response.pdf |date=July 9, 2016 }}, Encyclopædia Britannica, March 2006</ref>

<ref name="stothart">Chloe Stothart. [http://www.timeshighereducation.co.uk/story.asp?sectioncode=26&storycode=209408 "Web threatens learning ethos"] {{webarchive |url=https://web.archive.org/web/20121221140310/http://www.timeshighereducation.co.uk/story.asp?sectioncode=26&storycode=209408 |date=December 21, 2012 }} ''The Times Higher Education Supplement'', 2007, 1799 (June 22), p. 2.</ref>

<ref name="wwplagiarism">{{cite web |title = Plagiarism by Wikipedia editors |url = http://www.wikipedia-watch.org/psamples.html |publisher = Wikipedia Watch |date = October 27, 2006 |archiveurl = https://www.webcitation.org/5lXiLbptk?url=http://www.wikipedia-watch.org/psamples.html |archivedate = November 25, 2009 |deadurl = yes |df = mdy-all }}</ref>

<ref name="The Register-April">{{cite news |url = https://www.theregister.co.uk/2010/04/09/sanger_reports_wikimedia_to_the_fbi/ |work = The Register |date = April 9, 2010 |first = Cade |last = Metz |title = Wikifounder reports Wikiparent to FBI over 'child porn' |accessdate = April 19, 2010 }}</ref>

<ref name=AFP>{{cite news |last1 = Agence France-Presse |title = Wikipedia rejects child porn accusation |url = http://www.smh.com.au/technology/technology-news/wikipedia-rejects-child-porn-accusation-20100428-tsvh.html |work = The Sydney Morning Herald |date = April 29, 2010 }}</ref>

<ref name="David_Mehegan">{{cite news |first = David |last = Mehegan |title = Many contributors, common cause |url = http://www.boston.com/business/technology/articles/2006/02/13/many_contributors_common_cause |work = Boston Globe |date = February 13, 2006 |accessdate = March 25, 2007 }}</ref>

<ref name="user identification">{{cite web |title = The Authority of Wikipedia |url = http://www.public.iastate.edu/~goodwin/pubs/goodwinwikipedia.pdf |archiveurl = https://web.archive.org/web/20091122202231/http://www.public.iastate.edu/~goodwin/pubs/goodwinwikipedia.pdf |archivedate = November 22, 2009 |author = Jean Goodwin |year = 2009 |quote = Wikipedia's commitment to anonymity/pseudonymity thus imposes a sort of epistemic agnosticism on its readers |accessdate = January 31, 2011 }}</ref>

<ref name="ListOfWikipedias">{{cite web |url = https://en.wikipedia.org/wiki/Special:Statistics |title = Statistics |publisher = [[English Wikipedia]] |accessdate = June 21, 2008 |date = October 4, 2018 }}</ref>

<ref name="servers">{{cite web |url = http://wikitech.wikimedia.org/view/Server_roles |title = Server roles at wikitech.wikimedia.org |accessdate = December 8, 2009 |archiveurl = https://web.archive.org/web/20130116155841/http://wikitech.wikimedia.org/view/Server_roles |archivedate = January 16, 2013 |deadurl = yes }}</ref>

<ref name="WP_court_source">{{cite journal |last = Arias |first = Martha L. |date = January 29, 2007 |url = http://www.ibls.com/internet_law_news_portal_view.aspx?s=latestnews&id=1668 |title = Wikipedia: The Free Online Encyclopedia and its Use as Court Source |journal = Internet Business Law Services |accessdate = December 26, 2008 |archive-url = https://web.archive.org/web/20120520054827/http://www.ibls.com/internet_law_news_portal_view.aspx?s=latestnews&id=1668 |archive-date = May 20, 2012 |dead-url = yes |df = mdy-all }} (The name "''World Intellectual Property Office''" should however read "''World Intellectual Property Organization''" in this source.)</ref>

<ref name=twsY23>{{cite news |author = Lexington |title = Classlessness in America: The uses and abuses of an enduring myth |work = The Economist |quote = Socialist Labour Party of America [...] though it can trace its history as far back as 1876, when it was known as the Workingmen's Party, no less an authority than Wikipedia pronounces it "moribund". |date = September 24, 2011 |url = http://www.economist.com/node/21530100 |accessdate = September 27, 2011 }}</ref>

<ref name="Domesday Project">{{cite web |url = http://www.domesday1986.com/ |title = Website discussing the emulator of the Domesday Project User Interface |author = Heart Internet |accessdate = September 9, 2014 }}</ref>

<ref name="OurProjects">[[:foundation:Our projects|"Our projects"]], [[Wikimedia Foundation]]. Retrieved January 24, 2007.</ref>

<ref name="Orlowski18">{{cite news |first = Andrew |last = Orlowski |authorlink = Andrew Orlowski |url = https://www.theregister.co.uk/2006/09/18/sanger_forks_wikipedia |title = Wikipedia founder forks Wikipedia, More experts, less fiddling? |work = The Register |date = September 18, 2006 |quote = Larry Sanger describes the Citizendium project as a "progressive or gradual fork", with the major difference that experts have the final say over edits. |accessdate = June 27, 2007 }}</ref>

<ref name=Tancer>{{cite news |url = http://www.time.com/time/business/article/0,8599,1595184,00.html |title = Look Who's Using Wikipedia |author = Bill Tancer |date = May 1, 2007 |work = [[Time (magazine)|Time]] |quote = The sheer volume of content [...] is partly responsible for the site's dominance as an online reference. When compared to the top 3,200 educational reference sites in the US, Wikipedia is No. 1, capturing 24.3% of all visits to the category |accessdate = December 1, 2007 }}. [[Cf.]] Bill Tancer (Global Manager, Hitwise), [http://weblogs.hitwise.com/bill-tancer/2007/03/wikipedia_search_and_school_ho.html "Wikipedia, Search and School Homework"] {{webarchive |url=https://web.archive.org/web/20120325220239/http://weblogs.hitwise.com/bill-tancer/2007/03/wikipedia_search_and_school_ho.html |date=March 25, 2012 }}, ''[[Hitwise]]'', March 1, 2007.</ref>

<ref name=Woodson>{{cite news |url = https://www.reuters.com/article/internetNews/idUSN0819429120070708 |title = Wikipedia remains go-to site for online news |date = July 8, 2007 |author = Alex Woodson |agency = Reuters |quote = Online encyclopedia Wikipedia has added about 20 million unique monthly visitors in the past year, making it the top online news and information destination, according to Nielsen//NetRatings. |accessdate = December 16, 2007 }}</ref><ref name="365M">{{cite web |url = http://upload.wikimedia.org/wikipedia/meta/3/3a/TED2010%2C_Stuart_West_full_presentation_updated_with_January_data.pdf |title = Wikipedia's Evolving Impact: slideshow presentation at TED2010 |first = Stuart |last = West |date = |accessdate = October 23, 2015 }}</ref>

<ref name="bing WP research and referencing">{{cite web |url = http://www.bing.com/community/site_blogs/b/search/archive/2009/07/27/researching-with-bing-reference.aspxResearching |title = With Bing Reference |accessdate = September 9, 2014 |df = }}{{dead link|date=April 2019|bot=medic}}{{cbignore|bot=medic}}</ref>

<ref name="WP vandalism manipulation 1">{{srlink|Wikipedia:Vandalism|Vandalism}}. ''Wikipedia''. Retrieved November 6, 2012.</ref>

<ref name="WP CD selection 1">{{srlink|Wikipedia:Wikipedia CD Selection|Wikipedia CD Selection}}. Retrieved September 8, 2009.</ref>

<ref name="WP DB usage policy 1">{{srlink|Wikipedia:Database download|Wikipedia policies}} on data download</ref>

<ref name="J Sidener">{{Cite news |url = http://legacy.utsandiego.com/news/tech/personaltech/20061009-9999-mz1b9wikiped.html |title = Wikipedia family feud rooted in San Diego |last = Sidener |first = Jonathan |date = October 9, 2006 |publisher = [[The San Diego Union-Tribune]] |archive-url = https://web.archive.org/web/20161111074945/http://legacy.sandiegouniontribune.com/news/tech/personaltech/20061009-9999-mz1b9wikiped.html |archive-date = November 11, 2016 |access-date = May 5, 2009 }}</ref>

<ref name="NBC WP editorial warzone 1">{{cite web |url = http://sys03-public.nbcnews.com/technology/wikipedia-editorial-warzone-says-study-838793 |archive-url = https://archive.today/20140822010030/http://sys03-public.nbcnews.com/technology/wikipedia-editorial-warzone-says-study-838793 |dead-url = yes |archive-date = August 22, 2014 |title = Wikipedia is editorial warzone, says study |author = Coldewey, Devin |publisher = [[NBC News]] |website = Technology |date = June 21, 2012 |accessdate = October 29, 2012 }}</ref>

<!-- This reference is defined in [[English Wikipedia]] as of March 17, 2017 and transcluded here.<ref name="FMonday WP quality control 1">{{cite journal |url = http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/viewArticle/2721/2482 |title = Evaluating quality control of Wikipedia's featured articles |first = David |last = Lindsey |journal = First Monday |volume = 15 |issue = 4 |date = April 5, 2010 |accessdate = January 29, 2017 |doi = 10.5210/fm.v15i4.2721 |archive-url = https://web.archive.org/web/20121124044443/http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/viewArticle/2721/2482 |archive-date = November 24, 2012 |dead-url = yes |df = mdy-all }}</ref>-->

<!-- <ref name="autogenerated4">{{cite web |last = Sanger |first = Larry |title = What should we do about Wikipedia's porn problem? |url = http://larrysanger.org/2012/05/what-should-we-do-about-wikipedias-porn-problem |accessdate = July 26, 2012 }}</ref>


<ref name="WM dictionary 1">{{cite web |url = http://meta.wikimedia.org/w/index.php?title=Wikimedia_News&diff=prev&oldid=4133 |title = Announcement of Wiktionary's creation |publisher = meta.wikimedia.org |accessdate = July 14, 2012 }}</ref>

<ref name="emory disputes handled 1">{{cite journal |title = Wikitruth through Wikiorder |ssrn = 1354424 |format = |journal = Emory Law Journal |volume = 59 |issue = 1 |year = 2009 |page = 181 |author = David A. Hoffman |author2 = Salil K. Mehra }}</ref>


== Further reading ==

=== Academic studies ===

{{Main|Academic studies about Wikipedia}}


  • {{cite book|isbn =978-1-4214-1535-2|last=Leitch|first= Thomas|title=Wikipedia U: Knowledge, authority, and a liberal education in the digital age|year=2014}}
  • {{cite journal|last=Jensen|first= Richard|title=Military History on the Electronic Frontier: Wikipedia Fights the War of 1812|journal=The Journal of Military History|volume=76|issue=4 |date=October 2012|pages= 523–556|url=http://www.americanhistoryprojects.com/downloads/JMH1812.PDF}}
  • {{cite journal |title = Circadian Patterns of Wikipedia Editorial Activity: A Demographic Analysis |first = Taha |last = Yasseri |year = 2012 |journal = PLoS ONE |volume = 7 |author2 = Robert Sumi |author3 = János Kertész |issue = 1 |doi = 10.1371/journal.pone.0030091 |editor1-last = Szolnoki |editor1-first = Attila |page = e30091 |pmid = 22272279 |pmc = 3260192 |arxiv = 1109.1746 |bibcode = 2012PLoSO...7E0091Y }}
  • {{cite journal |ssrn = 1458162 |title = Wikipedia's Labor Squeeze and its Consequences |first = Eric |last = Goldman |year = 2010 |journal = Journal of Telecommunications and High Technology Law |volume = 8 }} ([http://blog.ericgoldman.org/archives/2010/02/catching_up_wit.htm A blog post by the author.])
  • {{cite journal |first = Finn |last = Nielsen |url = http://www.firstmonday.org/issues/issue12_8/nielsen/index.html |title = Scientific Citations in Wikipedia |journal = [[First Monday (journal)|First Monday]] |volume = 12 |issue = 8 |date = August 2007 |accessdate = February 22, 2008 |doi = 10.5210/fm.v12i8.1997 |arxiv = 0805.1154 |citeseerx = }}
  • {{cite journal |last = Pfeil |first = Ulrike |author2 = Panayiotis Zaphiris |author3 = Chee Siang Ang |title = Cultural Differences in Collaborative Authoring of Wikipedia |journal = Journal of Computer-Mediated Communication |year = 2006 |volume = 12 |issue = 1 |page = 88 |url = http://jcmc.indiana.edu./vol12/issue1/pfeil.html |doi = 10.1111/j.1083-6101.2006.00316.x |accessdate = December 26, 2008 }}
  • {{cite book|authors=Priedhorsky, Reid, Jilin Chen, Shyong (Tony) K. Lam, Katherine Panciera, [[Loren Terveen]], and [[John Riedl]]|title=Proceedings of the 2007 international ACM conference on Conference on supporting group work – GROUP '07 |chapter-url=http://portal.acm.org/citation.cfm?doid=1316624.1316663 |doi=10.1145/1316624.1316663|chapter=Creating, destroying, and restoring value in wikipedia |year=2007 |isbn=978-1-59593-845-9 |citeseerx=|pages=259–268}}
  • {{cite conference |first = Joseph |last = Reagle |title = Do as I Do: Authorial Leadership in Wikipedia |work = WikiSym '07: Proceedings of the 2007 International Symposium on Wikis |publisher = ACM |location = Montreal, Canada |year = 2007 |url = http://reagle.org/joseph/2007/10/Wikipedia-Authorial-Leadership.pdf |hdl=2047/d20002876 |accessdate = December 26, 2008 }}
  • {{cite book | first = Emiel | last = Rijshouwer | date = 2019 | title = Organizing Democracy. Power concentration and self-organization in the evolution of Wikipedia (PhD, Erasmus University Rotterdam) | oclc = 1081174169 | hdl = 1765/113937 | isbn = 978-9402813715 }} (Open access)

* [[Roy Rosenzweig|Rosenzweig, Roy]]. [https://web.archive.org/web/20090430201444/http://chnm.gmu.edu/resources/essays/d/42 Can History be Open Source? Wikipedia and the Future of the Past]. (Originally published in ''[[The Journal of American History]]'' 93.1 (June 2006): 117–146.)

  • {{cite journal |url = http://www.firstmonday.org/issues/issue12_4/wilkinson/index.html |title = Assessing the Value of Cooperation in Wikipedia |first = Dennis M. |last = Wilkinson |author2 = Bernardo A. Huberman |journal = First Monday |volume = 12 |issue = 4 |date = April 2007 |accessdate = February 22, 2008 |doi = 10.5210/fm.v12i4.1763 |arxiv = cs/0702140 |citeseerx = |bibcode = 2007cs........2140W }}
  • {{cite journal |url = http://abs.sagepub.com/content/57/5/664 |title = The Rise and Decline of an Open Collaboration Community |journal = American Behavioral Scientist |author = Aaron Halfaker |author2 = R. Stuart Geiger |author3 = Jonathan T. Morgan |author4 = John Riedl |accessdate = August 30, 2012 |doi = 10.1177/0002764212469365 |year = 2012 |volume = 57 |issue = 5 |page = 664 }}


* Maggio Lauren, Willinsky John, Steinberg Ryan, Mietchan Daniel, Wass Joseph, Dong Ting. "Wikipedia as a gateway to biomedical research: The relative distribution and use of citations in the English Wikipedia" (2017).

=== Books ===

{{Main|List of books about Wikipedia}}


  • {{cite book |first1 = Phoebe |last1 = Ayers |first2 = Charles |last2 = Matthews |first3 = Ben |last3 = Yates |title = How Wikipedia Works: And How You Can Be a Part of It |publisher = No Starch Press |location = San Francisco |year= 2008 |isbn = 978-1-59327-176-3 }}
  • {{cite book |last = Broughton |first = John |title = Wikipedia – The Missing Manual |publisher = O'Reilly Media |year = 2008 |isbn = 978-0-596-51516-4 |title-link = Wikipedia – The Missing Manual }} (See book review by Baker, as listed hereafter.)
  • {{cite book |last = Broughton |first = John |title = Wikipedia Reader's Guide |publisher = Pogue Press |location = Sebastopol |year = 2008 |isbn = 978-0-596-52174-5 }}
  • {{cite book |last = Dalby |first = Andrew |authorlink = Andrew Dalby |title = The World and Wikipedia: How We are Editing Reality |publisher = Siduri |year = 2009 |isbn = 978-0-9562052-0-9 }}
  • {{cite book |first1 = Dariusz |last1 = Jemielniak |title = Common Knowledge? An Ethnography of Wikipedia |publisher = [[Stanford University Press]] |location = Stanford, California |date = 2014 |isbn = 978-0-8047-8944-8 |title-link = Common Knowledge? An Ethnography of Wikipedia }}
  • {{cite book |last = Keen |first = Andrew |title = The Cult of the Amateur |publisher = Doubleday/Currency |year = 2007 |isbn = 978-0-385-52080-5 |authorlink = Andrew Keen |title-link = The Cult of the Amateur }} (Substantial criticisms of Wikipedia and other web 2.0 projects.)

** Listen to:

      • {{cite web |last = Keen |first = Andrew |url = https://www.npr.org/templates/story/story.php?storyId=11131872 |title = Does the Internet Undermine Culture? |publisher = National Public Radio, US|date = June 16, 2007 }} The NPR interview with A. Keen, Weekend Edition Saturday, June 16, 2007.
  • {{cite book |last = Lih |first = Andrew |authorlink = Andrew Lih |title = The Wikipedia Revolution: How a Bunch of Nobodies Created the World's Greatest Encyclopedia |publisher = Hyperion |location = New York |year = 2009 |isbn = 978-1-4013-0371-6 |title-link = The Wikipedia Revolution: How a Bunch of Nobodies Created the World's Greatest Encyclopedia }}
  • {{cite book |last = O'Sullivan |first = Dan |title = Wikipedia: a new community of practice? |url = https://books.google.com/books?id=htu8A-m_Y4EC |year = 2009 |publisher = Ashgate Publishing |isbn = 978-0-7546-7433-7 }}
  • {{cite book|authors=[[Sheizaf Rafaeli]] & Yaron Ariel|year=2008|chapter=Online motivational factors: Incentives for participation and contribution in Wikipedia |editor = Barak, A. |title = Psychological aspects of cyberspace: Theory, research, applications |pages = 243–267 |location = Cambridge, UK |publisher = [[Cambridge University Press]] }}
  • {{cite book |last = Reagle |first = Joseph Michael Jr. |title = Good Faith Collaboration: The Culture of Wikipedia |publisher = the MIT Press |location = Cambridge, Massachusetts|year = 2010 |isbn = 978-0-262-01447-2 |url = http://reagle.org/joseph/2010/gfc |accessdate = October 25, 2015 }}


=== Book review-related articles ===


* [[Nicholson Baker|Baker, Nicholson]]. [https://web.archive.org/web/20080303001807/http://www.nybooks.com/articles/21131 "The Charms of Wikipedia"]. ''[[The New York Review of Books]]'', March 20, 2008. Retrieved December 17, 2008. (Book rev. of ''The Missing Manual'', by John Broughton, as listed previously.)

* [[L. Gordon Crovitz|Crovitz, L. Gordon]]. [https://www.wsj.com/articles/SB123897399273491031 "Wikipedia's Old-Fashioned Revolution: The online encyclopedia is fast becoming the best."] (Originally published in [[The Wall Street Journal|''Wall Street Journal'']] online&nbsp;– April 6, 2009.)

* [[Virginia Postrel|Postrel, Virginia]], [https://psmag.com/social-justice/killed-wikipedia-93777 "Who Killed Wikipedia? : A hardened corps of volunteer editors is the only force protecting Wikipedia. They might also be killing it"], ''[[Pacific Standard]]'' magazine, November/December 2014 issue.


=== Learning resources ===


* [[v:wikipedia#Learning resources|Wikiversity list of learning resources]]. (Includes related courses, [[Web conferencing|Web-based seminars]], slides, lecture notes, text books, quizzes, glossaries, etc.)

* [http://www.cbc.ca/ideas/episodes/2014/01/15/the-great-book-of-knowledge-part-1/ The Great Book of Knowledge, Part 1: A Wiki is a Kind of Bus], ''[[Ideas (radio show)|Ideas, with Paul Kennedy]]'', [[CBC Radio One]], originally broadcast January 15, 2014. Webpage includes a link to the archived audio program (also [http://www.cbc.ca/ideas/popupaudio.html?clipIds=2430203709 found here]). The radio documentary discusses Wikipedia's history, development and its place within the broader scope of the trend to democratized knowledge. It also includes interviews with several key Wikipedia staff and contributors, including [[Kat Walsh]] and [[Sue Gardner]] (audio, 53:58, Flash required).


=== Other media coverage ===

{{See also|List of films about Wikipedia}}


  • {{cite news |last = Balke |first = Jeff |url = http://blogs.chron.com/brokenrecord/2008/03/for_music_fans_wikipedia_myspa.html |title = For Music Fans: Wikipedia; MySpace |work = [[Houston Chronicle]] |agency = Broken Record (blog) |date = March 2008 |accessdate = December 17, 2008 }}
  • {{Cite news |last=Borland |first=John |date=August 14, 2007 |title=See Who's Editing Wikipedia – Diebold, the CIA, a Campaign |url=https://www.wired.com/2007/08/wiki-tracker/ |archive-url=https://web.archive.org/web/20151116134820/https://www.wired.com/2007/08/wiki-tracker/ |archive-date=November 16, 2015 |dead-url=no |work=[[Wired (magazine)|Wired]] |access-date=October 23, 2018}}
  • {{cite news |url = https://www.nytimes.com/2007/07/01/magazine/01WIKIPEDIA-t.html |title = All the News That's Fit to Print Out |first = Jonathan |last = Dee |work = The New York Times Magazine |date = July 1, 2007 |accessdate = February 22, 2008 }}
  • {{cite news |first = Jim |last = Giles |title = Wikipedia 2.0&nbsp;– Now with Added Trust |url = https://www.newscientist.com/article/mg19526226.200 |date = September 20, 2007 |work = [[New Scientist]] |accessdate = January 14, 2008 }}
  • {{cite news |first = Mike |last = Miliard |title = Wikipedia Rules |url = http://thephoenix.com/Boston/Life/52864-Wikipedia-rules |work = [[The Phoenix (newspaper)|The Phoenix]] |date = December 2, 2007 |accessdate = February 22, 2008 }}
  • {{cite news |first = Marshall |last = Poe |authorlink = Marshall Poe |url = https://www.theatlantic.com/doc/200609/wikipedia |title = The Hive |work = [[The Atlantic]] Monthly |date = September 1, 2006 |accessdate = March 22, 2008 }}
  • {{cite news |first = Michael S. |last = Rosenwald |url = https://www.washingtonpost.com/wp-dyn/content/article/2009/10/22/AR2009102204715.html?hpid=topnews |title = Gatekeeper of D.C.'s entry: Road to city's Wikipedia page goes through a DuPont Circle bedroom |date = October 23, 2009 |work = The Washington Post |accessdate = October 22, 2009 }}
  • {{cite news |first = David |last = Runciman |url = http://www.lrb.co.uk/v31/n10/runc01_.html |title = Like Boiling a Frog |date = May 28, 2009 |work = London Review of Books |accessdate = June 3, 2009 }}
  • {{cite news |first = Chris |last = Taylor |url = http://www.time.com/time/magazine/article/0,9171,1066904-1,00.html |title = It's a Wiki, Wiki World |date = May 29, 2005 |work = [[Time (magazine)|Time]] |accessdate = February 22, 2008 }}
  • {{cite news |url = http://www.economist.com/science/tq/displaystory.cfm?story_id=11484062 |title = Technological Quarterly: Brain Scan: The Free-knowledge Fundamentalist |work = [[The Economist]] |date = June 5, 2008 |accessdate = June 5, 2008 |quote = Jimmy Wales changed the world with Wikipedia, the hugely popular online encyclopedia that anyone can edit. What will he do next? }}

* [https://www.independent.co.uk/life-style/gadgets-and-tech/features/is-wikipedia-cracking-up-1543527.html "Is Wikipedia Cracking Up?"] ''The Independent'', February 3, 2009.

* [https://www.bbc.co.uk/news/technology-24613608 "Wikipedia probe into paid-for 'sockpuppet' entries"], BBC News, October 21, 2013.

* [http://www.technologyreview.com/featuredstory/520446/the-decline-of-wikipedia/ "The Decline of Wikipedia"], ''MIT Technology Review'', October 22, 2013

* [http://www.capitalnewyork.com/article/city-hall/2015/03/8563947/edits-wikipedia-pages-bell-garner-diallo-traced-1-police-plaza "Edits to Wikipedia pages on Bell, Garner, Diallo traced to 1 Police Plaza"] (March 2015), ''[[Media in New York's Capital District|Capital]]''

* [https://motherboard.vice.com/read/wikipedia-zero-facebook-free-basics-angola-pirates-zero-rating Angola's Wikipedia Pirates Are Exposing Problems] (March 2016), ''[[Vice (magazine)|Motherboard]]''

* {{Cite web |url=http://fullmeasure.news/news/politics/dark-side-of-wikipedia |title=Dark Side of Wikipedia |access-date=April 17, 2016 |archive-url=https://web.archive.org/web/20160804110601/http://fullmeasure.news/news/politics/dark-side-of-wikipedia |archive-date=August 4, 2016 |dead-url=yes |df=mdy-all }} ''[[Full Measure with Sharyl Attkisson]]'', April 17, 2016. <small>(Includes video.)</small>

  • {{cite web |last1 = Wales |first1 = Jimmy |title = How Wikipedia Works |url = https://www.cato.org/multimedia/cato-daily-podcast/how-wikipedia-works |website = cato.org |publisher = [[Cato Institute]] |date = December 9, 2016 |quote = Jimmy Wales, founder of Wikipedia, discusses the site, how it’s treated by governments, and how it’s fueled by its users. }}


== External links ==

{{Sister project links|collapsible=true|Wikipedia|voy=Wikivoyage:Cooperating with Wikipedia|d=Q52|s=Category:Wikipedia|n=Category:Wikipedia|m=Wikipedia|mw=Wikipedia|species=no}}

  • {{official website|https://www.wikipedia.org|mobile=https://en.m.wikipedia.org}} – multilingual portal (contains links to all language editions) (wikipedia.com still redirects here)
  • {{Dmoz|Computers/Open_Source/Open_Content/Encyclopedias/Wikipedia}}
  • {{Guardian topic}}

* [http://topics.nytimes.com/top/news/business/companies/wikipedia/index.html Wikipedia] topic page at ''[[The New York Times]]''

* [http://www.ted.com/index.php/talks/jimmy_wales_on_the_birth_of_wikipedia.html Video of TED talk by Jimmy Wales on the birth of Wikipedia]


{{Wiki topics}}

{{Wikimedia Foundation}}


{{Authority control}}

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[[Category:Wikipedia| ]]

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[[Category:Internet properties established in 2001]]

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