Wisdom of the Crowds: Decentralized Knowledge Construction in Wikipedia

provides an "explanation of how open content systems successfully achieve high quality content."

"Surowiecki (2005) for assuring that the aggregate contributions of a crowd are high quality: (a) a large number of contributors and opinions (e.g. crowd size), (b) diversity of ideas and opinions, and (c) appropriate mechanisms for aggregating the opinions (e.g. the participants are able to express their opinions independent of influence from others, and aggregation techniques combine the independent opinions)."

"The number of people (i.e the number of ideas and opinions) in a crowd directly impacts the crowd’s aggregate knowledge." ... the bigger the group, the faster it converges to correct answer, if each individual has prob > 0.5 of choosing correct answer (Jury Theorem).

"Diversity also impacts the crowd’s wisdom and is expected in large groups. ... Mannix and Neale (2005), reviewing fifty years of diversity research, point out how differences in group members’ skills and knowledge are associated with increased group performance."

"Some (e.g. Lih 2004, Stvilia et al. 2005) argue that the number of contributors and edits in an article is associated with an article’s quality. A large author-base ensures diversity of opinions (Surowiecki 2005), and Wikipedia contributors exhibit diversity in terms of background and interests (Bryant et al. 2005). Diversity of opinion is evident in an article’s discussion page (where conflicting opinions are deliberated), and high-quality pages (i.e., those selected as Featured Articles) have larger discussion pages (Stvilia et al. 2005)."

To test Wisdom of Crowds at work ... "Size is estimated through two proxies (1) the number of unique contributors to an article (number of authors), and (2) the total number of contributions (number of edits)."

"we employ two proxies [for diversity]: (1) the number of words in an article’s discussion page, and (2) the number of edit wars (where Wikipedia’s defines an edit war as three edits by a particular user within 24 hours, with edits from other users in between). The greater the variance in opinions is, the more likely the authors are to engage in edit wars and argue their opinions on the discussion page."

Results: "Second, a causal relationship between Diversity and the dependent variable (Quality) is established, and is statistically significant. Finally, size has a significant effect on Diversity." ... "It is interesting to note that the coefficient for the path linking Size to Quality has a negative sign."