Recent (and past data) on Wikipedia's contributors and their impact.
- Wikipedia is the number 10 Web site in the United States. In July 2009, it had 62 million unique visitors and about 10 million registered users. Of the top ten, Wikipedia is the only non-profit website. (source)
- The English version of Wikipedia has over 3 million articles and over 17 million pages. (source)
- Worldwide, Wikipedia has over 10 million articles in over 250 languages. (source)
- In July 2007, about 2,200 articles were added daily to the encyclopedia; as of August 2009, that average is 1,300. (source)
- Early on Jimmy Wales, founder of Wikipedia performed a study that found that over 50% of all Wikipedia edits are done by just .7% of the users (at the time: 524 people). (source)
- The top 15% of the most prolific editors account for 90% of Wikipedia's edits. (source)
- The top 10% of editors (by edit count) are credited with 86% of PWVs (the number of times a word introduced by an edit is viewed), the top 1% about 70%, and the top 0.1% (4200 users) attributed to 44% of PWVs, i.e. nearly half of Wikipedia's "value" as measured in this study. The top 10 editors (by PWV) contributed only 2.6% of PWVs, and only three of them were in top 50 by edit count. (source)
- The influence of administrator edits on content has steadily diminished since 2003, when administrators performed roughly 50% of total edits, to 2006 when only 10% of the edits were performed by administrators. (source)
- Wiki edit completion (select edit but not save) rates: wikitravel 5% (old statistic) wikihow 30% wikia 90% -the new WYSIWYG editor helped. (source)
- Only 13% of the online encyclopedia’s contributors are women. (source)
- Altruism and fact-checking are the top motivations of contributors. About 73% of contributors “like the idea of sharing knowledge and want to contribute to it,” while 69% said “I saw an error I wanted to fix. (source)
- Contributors are more likely to have a Masters degree (19%) or a Ph.D. (4.4%) than readers (17% and 2.3%, respectively). (source)
- People would be more likely to contribute to the site if “I knew there were specific topic areas that needed my help” (41%), followed by “It was clear to me that other people would benefit from my efforts” (36%). (source)
- The reasons for not contributing, include time constraints, satisfaction with just reading entries or simply not knowing how to edit the pages. One quarter, however, are afraid of making a mistake “and getting ‘in trouble’ for it.” (source)
- The male/female ratio is closer among those who read entries but don’t write or edit them: 69% men to 31% women. (source)
- Technical and scientific entries have the highest participation by self-identified experts, while geographic and place-related pages have relatively low levels of expertise but more contributors. (source)
- The community of authors in the top ten Wikipedias reaches a steady state in 2006 or 2007 in most versions. (source)
- Coordination among authors in the top ten Wikipedias is mostly steady over time. JP/NL/PO do not use talk pages very much; English and French use it like crazy. (source)
- The lack of new core members seriously threatens the scalability of the top-ten language version. The eldest, top-active contributors are responsible for the majority of revisions. Since the number of core authors has reached a steady-state (due to the leverage in the total number of active authors per month), the group of authors providing the primary source of effort in the revision of quality articles has stalled. (source)
- Half life for average lifetime of Wikipedia volunteer authors is about 200 days and less than 30 in PT and EN. (source)
- There is a 10% increase in chance of approval for a Wikipedia article for every 3800 edits. (source)
- The growth of Wikipedia has been fueled by its dominant position in Google search results. About 50% of search engine traffic to Wikipedia comes from Google. (source)