Various
Wikipedians have
criticized Wikipedia's large and growing regulation, which includes more than fifty policies and nearly 150,000 words Critics have stated that Wikipedia exhibits
systemic bias. In 2010, columnist and journalist
Edwin Black described Wikipedia as being a mixture of "truth, half-truth, and some falsehoods". Articles in
The Chronicle of Higher Education and
The Journal of Academic Librarianship have criticized Wikipedia's "
undue-weight policy", concluding that Wikipedia explicitly is not designed to provide correct information about a subject, but rather focus on all the major viewpoints on the subject, give less attention to minor ones, and creates omissions that can lead to false beliefs based on incomplete information. Journalists
Oliver Kamm and
Edwin Black alleged (in 2010 and 2011, respectively) that articles are dominated by the loudest and most persistent voices, usually by a group with an "ax to grind" on the topic. A 2008 article in
Education Next journal concluded that as a resource about controversial topics, Wikipedia is subject to manipulation and
spin. In 2020,
Omer Benjakob and
Stephen Harrison noted that "Media coverage of Wikipedia has radically shifted over the past two decades: once cast as an intellectual frivolity, it is now lauded as the 'last bastion of shared reality' online." Multiple news networks and pundits have accused Wikipedia of being
ideologically biased. In February 2021,
Fox News accused Wikipedia of whitewashing
communism and
socialism and having too much "
leftist bias". Wikipedia co-founder
Larry Sanger, who left Wikipedia in 2002 to establish competing websites, has said that Wikipedia had become "propaganda" for the left-leaning "establishment" and warned the site can no longer be trusted. In 2022, libertarian
John Stossel opined that Wikipedia, a site he financially supported at one time, appeared to have gradually taken a significant turn in bias to the political left, specifically on political topics. Some studies suggest that Wikipedia (and in particular the English Wikipedia) has a "western
cultural bias" (or "pro-western bias") or "Eurocentric bias", reiterating, says Anna Samoilenko, "similar biases that are found in the 'ivory tower' of academic historiography". Carwil Bjork-James proposes that Wikipedia could follow the diversification pattern of contemporary scholarship
Accuracy of content Articles for traditional encyclopedias such as
Encyclopædia Britannica are written by
experts, lending such encyclopedias a reputation for accuracy. 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." The findings by
Nature were disputed by
Encyclopædia Britannica, and in response,
Nature gave a rebuttal of the points raised by
Britannica. 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
Natures manual selection of articles, in part or in whole, for comparison), absence of statistical analysis (e.g., of reported
confidence intervals), and a lack of study "statistical power" (i.e., owing to small
sample size, 42 or 4 × 101 articles compared, vs >105 and >106 set sizes for
Britannica and the English Wikipedia, respectively). 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. Concerns have been raised by
PC World in 2009 regarding the lack of
accountability that results from users' anonymity, the insertion of false information,
vandalism, and similar problems.
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". 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, as well as relevant information being 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.
Amy Bruckman has argued that, due to the number of reviewers, "the content of a popular Wikipedia page is actually the most reliable form of information ever created". In September 2022,
The Sydney Morning Herald journalist Liam Mannix noted that: "There's no reason to expect Wikipedia to be accurate ... And yet it [is]." Mannix further discussed the multiple studies that have proved Wikipedia to be generally as reliable as
Encyclopædia Britannica, summarizing that "...turning our back on such an extraordinary resource is... well, a little petty." Critics argue that Wikipedia's open nature and a lack of proper sources for most of the information makes it unreliable. Some commentators suggest that Wikipedia may be reliable, but that the reliability of any given article is not clear. Wikipedia's open structure inherently makes it an easy target for
Internet trolls,
spammers, and various forms of paid advocacy seen as counterproductive to the maintenance of a neutral and verifiable online encyclopedia. In response to
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. The article stated that: "Beginning Monday [from the date of the 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. Wales stresses that encyclopedias of any type are not usually appropriate to use as citable sources, and should not be relied upon as authoritative. 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
syllabi, although without realizing the articles might change. In June 2007,
Michael Gorman, former president of the
American Library Association, condemned Wikipedia, along with Google, 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 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." 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
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. 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 one percent' of Wikipedia's medical articles have passed." 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). Wikipedia contains materials that some people may find objectionable, offensive, or pornographic. The "Wikipedia is not censored" policy has sometimes proved controversial: in 2008, Wikipedia rejected an online petition against the inclusion of
images of Muhammad in the
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 among other countries. Through its "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. 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". An editorial in
The Guardian in 2014 claimed that more effort went into providing references for
a list of female porn actors than a
list of women writers.
Systemic biases Wikipedia's policies may limit "its capacity for truly representing global knowledge". For example, Wikipedia only considers published sources to be reliable.
Oral knowledge of Indigenous cultures is not always reflected in print. Marginalized topics are also more likely to lack significant coverage in reliable sources. Wikipedia's content is therefore limited as a result of larger systemic biases.
Academic studies of Wikipedia have shown that the average contributor to the English Wikipedia is an educated, technically inclined white male, aged 15–49, from a developed, predominantly Christian country. The corresponding point of view (POV) is over-represented. This systemic bias in editor demographic results in
cultural bias,
gender bias, and
geographical bias on Wikipedia. There are two broad types of bias, which are
implicit (when a topic is omitted) and
explicit (when a certain POV is over-represented in an article or by references). Across 30 language editions of Wikipedia, historical articles and sections are generally
Eurocentric and focused on recent events.
Explicit content Wikipedia has been criticized for allowing information about 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, illustrations of
zoophilia, and photos from
hardcore pornographic films in its articles. It also has non-sexual
photographs of nude children. The Wikipedia article about
Virgin Killer—a 1976 album from the German rock 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 providers 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. 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
US federal obscenity law. 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
PROTECT Act of 2003.
Wikimedia Foundation spokesman Jay Walsh strongly rejected Sanger's accusation, Critics, including
Wikipediocracy, noticed that many of the pornographic images deleted from Wikipedia since 2010 have reappeared.
Privacy One
privacy concern in the case of Wikipedia regards one's right to remain a
private citizen rather than a
public figure in the eyes of the law. It is a battle between the right to be anonymous in
cyberspace and the right to be anonymous in
real life. The Wikimedia Foundation's
privacy policy states, "we believe that you shouldn't have to provide personal information to participate in the free knowledge movement", and states that "personal information" may be shared "For legal reasons", "To Protect You, Ourselves & Others", or "To Understand & Experiment". In January 2006, a German court ordered the
German Wikipedia shut down within Germany because it stated the full name of
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. Wikipedia has a "" that uses Znuny, a
free and open-source software fork of
OTRS 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. In late April 2023, the Wikimedia Foundation announced that Wikipedia will not submit to any age verifications that may be required by the UK's
Online Safety Bill legislation. Rebecca MacKinnon of the Wikimedia Foundation said that such checks would run counter to the website's commitment to minimal data collection on its contributors and readers.
Sexism Wikipedia was described in 2015 as harboring a battleground culture of
sexism and
harassment. The perceived tolerance of abusive language was a reason put forth in 2013 for the gender gap in Wikipedia editorship.
Edit-a-thons have been held to encourage female editors and increase the coverage of women's topics. In May 2018, a Wikipedia editor rejected a submitted article about
Donna Strickland due to lack of coverage in the media. Five months later, Strickland won a
Nobel Prize in Physics "for groundbreaking inventions in the field of laser physics", becoming the third woman to ever receive the award. Prior to winning the award, Strickland's only mention on Wikipedia was in the article about her collaborator and co-winner of the award
Gérard Mourou. Purtill attributes the issue to the gender bias in media coverage.
Nine Theses "Nine Theses" refers to a reform proposal published by Larry Sanger in October 2025. Sanger's
Nine Theses on Wikipedia presents a critical assessment and reform agenda for Wikipedia. The proposal is part of his broader effort to address what Sanger perceives as systemic issues within Wikipedia, which include, ideological bias, lack of transparency in the editor hierarchies, and an ineffective consensus-based decision-making procedure. == Operation ==