Wikipedia , free Internet-based encyclopaedia , started in 2001, that operates under an open-source management style. It is overseen by the nonprofit Wikimedia Foundation. Wikipedia uses a collaborative software known as wiki that facilitates the creation and development of articles. Although some highly publicized problems have called attention to Wikipedia’s editorial process, they have done little to dampen public use of the resource, which is one of the most-visited sites on the Internet .

By 2006 the English-language version of Wikipedia had more than one million articles, and by the time of its 10th anniversary in 2011 it had surpassed 3.5 million. However, while the encyclopaedia continued to expand at a rate of millions of words per month, the number of new articles created each year gradually decreased, from a peak of 665,000 in 2007 to 374,000 in 2010. In response to this slowdown, the Wikimedia Foundation began to focus its expansion efforts on the non-English versions of Wikipedia, which by 2011 numbered more than 250. With some versions having already amassed hundreds of thousands of articles—the French and German versions both boasted more than one million—particular attention was paid to languages of the developing world, such as Swahili and Tamil, in an attempt to reach populations otherwise underserved by the Internet. One impediment to Wikipedia’s ability to reach a truly global audience, however, was the Chinese government’s periodic restrictions of access to some or all of the site’s content within China .

In 1996 Jimmy Wales , a successful bond trader, moved to San Diego , California , to establish Bomis, Inc., a Web portal company. In March 2000 Wales founded Nupedia , a free online encyclopaedia, with Larry Sanger as editor in chief. Nupedia was organized like existing encyclopaedias, with an advisory board of experts and a lengthy review process. By January 2001 fewer than two dozen articles were finished, and Sanger advocated supplementing Nupedia with an open-source encyclopaedia based on wiki software . On January 15, 2001, Wikipedia was launched as a feature of Nupedia.com, but, following objections from the advisory board, it was relaunched as an independent Web site a few days later. In its first year Wikipedia expanded to some 20,000 articles in 18 languages, including French, German, Polish, Dutch, Hebrew, Chinese, and Esperanto. In 2003 Nupedia was terminated and its articles moved into Wikipedia.

The central policy of inviting readers to serve as authors or editors creates the potential for problems as well as their at least partial solution. Not all users are scrupulous about providing accurate information, and Wikipedia must also deal with individuals who deliberately deface particular articles, post misleading or false statements, or add obscene material. Wikipedia’s method is to rely on its users to monitor and clean up its articles. Trusted contributors can also receive administrator privileges that provide access to an array of software tools to speedily fix Web graffiti and other serious problems.

In some respects Wikipedia’s open-source production model is the epitome of the so-called Web 2.0 , an egalitarian environment where the web of social software enmeshes users in both their real and virtual-reality workplaces. The Wikipedia community is based on a limited number of standard principles. One important principle is neutrality. Another is the faith that contributors are participating in a sincere and deliberate fashion. Readers can correct what they perceive to be errors, and disputes over facts and over possible bias are conducted through contributor discussions. Three other guiding principles are to keep within the defined parameters of an encyclopaedia, to respect copyright laws, and to consider any other rules to be flexible. The last principle reinforces the project’s belief that the open-source process will make Wikipedia into the best product available, given its community of users. At the very least, one by-product of the process is that the encyclopaedia contains a number of publicly accessible pages that are not necessarily classifiable as articles. These include stubs (very short articles intended to be expanded) and talk pages (which contain discussions between contributors).

Issues and controversies

Reliance on community self-policing has generated some problems. In 2005 the American journalist John L. Seigenthaler, Jr., discovered that his Wikipedia biography falsely identified him as a potential conspirator in the assassinations of both John F. Kennedy and Robert F. Kennedy and that these malicious claims had survived Wikipedia’s community policing for 132 days. The author of this information could not be easily identified, since all that is known about unregistered contributors is their computers’ IP, or Internet protocol, addresses (many of which are dynamically generated each time a user goes online). (The contributor later confessed and apologized, saying that he wrote the false information as a joke.) The Seigenthaler case prompted Wikipedia to prohibit unregistered users from editing certain articles. Similar instances of vandalism later led site administrators to formulate a procedure, despite protests from some contributors, by which some edits would be reviewed by experienced editors before the changes could appear online.

Although Wikipedia has occasionally come under fire for including information not intended to be widely disseminated—such as images of the 10 inkblots used by psychologists in the Rorschach Test—it has also adapted its philosophy of openness in certain cases. For instance, after New York Times reporter David S. Rohde was kidnapped by Taliban militants in Afghanistan in 2008, his employer arranged with Wikipedia for news of the incident to be kept off the Web site on the grounds that it could endanger Rohde’s life. The site’s administrators complied, in the face of repeated attempts by users to add the information, until after Rohde’s eventual escape. Additionally, in 2010 it was revealed that there was a cache of pornographic images, including illegal depictions of sexual acts involving children, on Wikimedia Commons, a site maintained by the Wikimedia Foundation that served as a repository of media files for use in all Wikimedia products. Although there were no such illegal images on Wikipedia itself, the ensuing scandal prompted Jimmy Wales, who personally deleted many of the Commons files, to encourage administrators to remove any prurient content from Wikimedia sites.

Wikipedia administrators also have the power to block particular IP addresses—a power they used in 2006 after it was found that staff members of some U.S. congressional representatives had altered articles to eliminate unfavourable details. News of such self-interested editing inspired Virgil Griffith, a graduate student at the California Institute of Technology, to create Wikipedia Scanner, or WikiScanner, in 2007. By correlating the IP addresses attached to every Wikipedia edit with their owners, Griffith constructed a database that he made available on the Web for anyone to search through. He and other researchers quickly discovered that editing Wikipedia content from computers located within corporations and in government offices was widespread. Although most of the edits were innocuous—typically, individuals working on subjects unrelated to their positions—a pattern did seem to emerge of many articles being edited to reflect more favourably on the editors’ hosts.

Debates about the utility of Wikipedia proliferated especially among scholars and educators, for whom the reliability of reference materials was of particular concern. While many classrooms, at nearly all grade levels, discouraged or prohibited students from using Wikipedia as a research tool, in 2010 the Wikimedia Foundation recruited several public policy professors in the United States to develop course work wherein students contributed content to the Wikipedia site. As Wikipedia became a seemingly inescapable part of the Internet landscape, its claims to legitimacy were further bolstered by an increasing number of citations of the encyclopaedia in U.S. judicial opinions, as well as by a program administered by the German government to work with the German-language site to improve its coverage of renewable resources.

The number of active editors (i.e., those who edit more than 100 articles a month) peaked in 2007 and as of 2017 had declined by about a third. Various factors were blamed for this decline. Wikipedia’s bureaucratic culture with its complex norms and its reliance on automated procedures that tended to reject new edits were seen as discouraging to new editors. Editing the articles requires knowledge of a specialized markup language that is difficult to edit on smartphones and tablets. Surveys of Wikipedia editors have revealed a persistent gender gap; only about 10–20 percent of the editors are women. In response to concerns about this gender gap and how it is reflected in the encyclopaedia, Wikipedia began about 2012 to encourage “edit-a-thons,” in which editors come together at events devoted to increasing the site’s coverage of such subjects as feminism and women’s history. Whether or not Wikipedia can solve these demographic problems, it has undoubtedly become a model of what the collaborative Internet community can and cannot do.