The Answer Place
Wikipedia needs no introduction, which in itself is a kind of introduction, acknowledging its global role as our go-to information source.
The collection of online encyclopedias—with editions in more than 200 major languages—is the internet’s sixth most visited site, drawing more eyeballs than eBay, Amazon, or Twitter. It’s the only top website that’s non-commercial, open source, and, most important, created by users…and edited by anyone.
Impact
Ask Wikipedia
If you wanted to learn about Wikipedia, there’s a good chance you’d look it up on Wikipedia. With 18 billion page views monthly, it has become the default first (and often last) stop for research.
The software behind Wikipedia is relatively simple. But the site’s impact has been enormous. Its crowd-sourced articles tap into a worldwide community of experts and editors, democratizing the process of sharing and updating information.
Photo © Quim Dasquens
Escaldàrium: Festival of Fire and Water, Caldes de Montbui, Barcelona, Spain, July 2014
Wikipedias for smaller or embattled languages, like Catalan, Maltese, and Kiswahili, become rallying points for preserving cultural traditions. New editors are often warmly welcomed, rather than forced to prove themselves as in major-language Wikipedias.
Who to Believe?
We need reliable information. But how and where to get it? Ask an expert, or tap into the wisdom of crowds? There aren’t enough experts to update every topic. Yet crowds can be swayed by fads or drawn into “edit wars.”
Wikipedia’s solution? Trust crowds, but not for new information. Instead, have them summarize what’s already published!

Credit: Wikipedia, The Free Encyclopedia, accessed August 19, 2016
”John Cena” article with references
Articles must cite sources! One of Wikipedia’s five pillars is “no original research”—a good editor accurately summarizes what is already published. This short article on a popular wrestler has 398 references!

Credit: Wikipedia, The Free Encyclopedia, accessed August 19, 2016
”George W. Bush” article and revision history
Articles evolve with input from different editors. For controversial topics, past edits dwarf the current article. “George W. Bush” has had 46,008 002 edits by 14,507 editors—more than 3,000 encyclopedia pages!
A Work in Progress
Throughout history, most information sources were static. Printed encyclopedias took years to produce, and were updated only occasionally, if ever.
Wikipedia, by contrast, is a living resource, with continual corrections and additions. So it’s rarely outdated. But that makes it vulnerable to shifting interpretations, as well as attempts at self-promotion.

Credit: Wikipedia, The Free Encyclopedia, accessed August 19, 2016
“United Kingdom European Union membership referendum, 2016” article
If as George Helgesen Fitch said journalism is “the first rough draft of history,” then Wikipedia is trying to be the next draft. Major breaking events can get Wikipedia updates within minutes, like the United Kingdom’s European Union exit (a.k.a. “Brexit”) on June 23, 2016.

Credit: Wikipedia, The Free Encyclopedia, accessed August 19, 2016
”Tony Robbins” article with promotional content warning
How can Wikipedia prevent editors from using articles to promote themselves or their causes? Blatantly biased edits and articles get deleted. Others get warning flags, like this one.

Pages on surgery, hydraulics, and shipping technology, Encyclopédia, or a Systematic Dictionary of the Sciences, Arts, and Crafts, edited by Denis Diderot and Jean le Rond d’Alembert, 1751-1772
This massive project in Enlightenment France was radically inclusive. It sought to make all knowledge accessible to all and incorporated current information from various trades as well as the “high” subjects of traditional encyclopedias.
Technology
Simple But Powerful
The brilliance of Wikipedia isn’t its software, which is technically straightforward. Rather, it’s the ideas behind that software—and its implementation.
Wikipedia articles accept constant additions from users worldwide. One key to making that work is the software’s built-in “undo” features, essential for a user-created resource where changes sometimes must be rolled back.

Credit: Wikipedia, The Free Encyclopedia, accessed August 19, 2016
”Computer History Museum” article (top) and markup language (bottom)
Clicking “edit” on a Wikipedia article lets you see and change the underlying, raw markup language. You can also choose a friendlier visual editor that looks like a word processor (not shown).
Open Source Collaboration
Open source software lets anybody study the underlying code, or copy it to create their own personalized version. “Open content” knowledge is similarly open to improvement and reuse.
Wikipedia is open content and powered by open source software. It is also the most famous “wiki”—software designed to enable collaborative writing.

Credit: By NicoBZH from Saint Etienne–Loire, France, CC BY-SA 2.0, via Wikimedia Commons
Richard Stallman, father of the Free Software movement
The free software movement opposed proprietary control over code and inspired the later open source and open content communities. Wikipedia adapted key open source tenets, like sharing and the right to re-use other’s work, to its encyclopedia.
Creating a Community
If you build it, they will come. And write. And research. And edit.
Wikipedia is a global community with over 100,000 volunteer editors and writers. To ensure that other volunteers don’t undo their work, contributors need to follow the rules. That means summarizing published information, not presenting original research or opinions.

Credit: By Gus Freedman (Wikimedia Foundation Inc.), CC BY-SA 2.5, via Wikimedia Commons
Wikimania conference, Cambridge, Massachusetts, 2006
Each year as many as 1,500 members of the Wikimedia community come together for a “tribal meeting” called Wikimania. Session topics range from copyright reform to supporting local editors to hacker tips.

Credit: By Victorgrigas (own work), CC BY-SA 3.0, via Wikimedia Commons
Wikimedia Foundation offices, July 19, 2011, San Francisco, California
Wikipedia has always had a central office of some sort, since it grew out of the commercial Nupedia. Today, the nonprofit Wikimedia Foundation staff of around 280 oversees fundraising, computing infrastructure, and software.

Credit: By PiRSquared17 (own work), CC0, via Wikimedia Commons
Chart of Wikipedia roles, August 12, 2014
Wikipedia started simple. But today some editors are Administrators, or Bureaucrats, or Stewards, or Reviewers, or Researchers, etc. in a sprawling hierarchy. The organization’s policy documents would fill a 400-page book.
Meet the “Staff”
Why do so many people, from over 150 countries, donate their time?
Motivations are as diverse as the contributors themselves. They range from the urge to add to—or correct—common knowledge, to showing off expertise or keeping alive minority languages such as Maltese and Catalan.

Credit: By EneasMx (own work), CC BY-SA 4.0, via Wikimedia Commons
Wikimania 2015, Museo Soumaya, Mexico City
Each year, the Wikimania conference pays special tribute to its host city. In 2015 Wikimania focused on quality control and digital rights in Latin America and other countries, like including Brazil, Spain, and Portugal.

Photograph by Dwi Satria Utama, CC BY 4.0, via Wikimedia Commons
Siska Doviana with Wikipedia Indonesia tutorial sign, Library of Goethe-Institut Jakarta, November 16, 2016
Siska Doviana started making thousands of edits to Indonesian Wikipedia from a keyboard attached to her mobile phone. She now heads the nonprofit Wikimedia Indonesia.
History
All the World's Knowledge
From ancient Egypt’s Library of Alexandria to 15th century China’s Yongle Encyclopedia, people have long sought to collect and organize the world’s information.
Twentieth century visionaries such as Paul Otlet and Douglas Engelbart conceived technologies to make that process collaborative, incorporating contributions from all kinds of people. But Wikipedia was the first to realize such collaboration on a large scale.

Courtesy of the Mundaneum Archives Centre
Palais Mondial (World Palace), later Mundaneum, Brussels, Belgium, ca. 1900
Paul Otlet and Henri La Fontaine sought to organize all the information in the world. Their Mundaneum had 15 million cards on thousands of topics. Otlet also experimented with microfilm, photocells, televised documents, and telex.
The Road to Wikipedia
The World Wide Web began as a collaborative medium, but its authoring features disappeared early. Ward Cunningham’s “wiki” software mimicked some of those lost capabilities.
In the late 1990s, a struggling commercial online encyclopedia called Nupedia launched a wiki to generate articles, which experts would then edit and refine.

Credit: By Andrew Laing (Wiki-Wiki!!!), CC BY-SA 2.0, via Wikimedia Commons
Wiki-Wiki airport bus, January 25, 2007
Wiki inventor Ward Cunningham learned the Hawaiian word for “quickly”—wiki—when he took the airport bus in Honolulu. It struck him as the perfect name for his new, instant collaboration system: WikiWikiWeb.

Left: Credit: By Carrigg Photography for the Wikimedia Foundation (own work), CC BY-SA 3.0, via Wikimedia Commons
Left-Ward Cunningham and Right-Original WikiWikiWeb
The web had originally been designed as a collaborative medium. Cunningham’s “Wiki” software, WikiWikiWeb, was meant to add back that feature within shared bases of knowledge.

Ward Cunningham, Inventor of the Wiki
Going Live…Then Going Viral
After its 2001 launch, Wikipedia—the wiki created to generate raw articles for online encyclopedia Nupedia—swiftly eclipsed its parent. But explosive growth sparked tussles between owner Jimmy Wales and Editor-in-Chief Larry Sanger, author of editing rules that still govern Wikipedia.
Wales favored ditching the experts and trusting crowd sourcing. Sanger preferred keeping the experts, but ended up leaving himself.
Growing Pains
Dizzyingly fast expansion strained Wikipedia’s code. In 2002 volunteer programmers undertook a massive rewrite to handle the traffic.
Growth also brought headaches, from digital graffiti to bogus articles that chronicled everything from phony wars to the (fake) pet crocodile of 18th-century English poet Lord Byron. A reassuring study, however, claimed claims Wikipedia was is as reliable as the venerable Encyclopedia Britannica.

Courtesy of the Sanger Institute, Genome Research Limited
Heinrich Magnus Manske, core MediaWiki programmer
Magnus Manske was a major contributor to Nupedia and wrote the first dedicated Wiki software for Wikipedia, introducing many core features. He also started the German Wikipedia, the second after English..