Anonymous users of the online encyclopedia Wikipedia may provide content of comparable quality to that provided by registered users, according to an April 2007 study conducted by Dartmouth students and faculty.
The project, which grew out of an earlier study focused on trust in computing, was conceived by professor Denise Anthony, chair of the sociology department, computer science professor Sean Smith and Tim Williamson '05, a former computer science major.
The Wikipedia study analyzed the relative number of contributions and the length of time for which they remained unchanged between registered users, or "Zealots," and anonymous users, or "Good Samaritans." The research aimed to determine whether content quality is better for Zealots, who are motivated by reputation in the Wikipedia community to produce accurate articles.
A computer program written by Williamson randomly selected about 1,700 of each type of user from two foreign language versions of the encyclopedia, and then compared contribution statistics for each group. The Dutch and French versions of the encyclopedia were chosen for the study after initial attempts to use the English version of the site failed, due to its considerably larger size.
The results showed that, while registered users produced more total content, the quality of the contributions was higher for Good Samaritans than for Zealots.
These findings, according to the text of the study, were "novel and unexpected."
"If you're registered, you can track the [user's] reputation," Anthony said. In contrast, with anonymous users, "there's no way to reward their contribution."
The study also found that content retention rates fall for Good Samaritans with more contributions, while the rates rise for registered users. This is likely due to extensive writing by anonymous vandals with "negative interest in the collective good," according to the study.
Anthony said she believes the study has applications beyond computing and the Internet for the wider realm of sociology and collective action. Despite the large body of literature on collectively produced goods like Wikipedia, controlled laboratory conditions often exclude the impact of Good Samaritans, whose contributions are spontaneous, Anthony said.
The study has been met with considerable interest in the academic community, due in part to Wikipedia's status as a scholarly cause celebre. A preliminary version of the paper was presented during an Economic Sociology and Technology Conference at Cornell University in 2005.
Anthony said it is important to note that the study does not make claims about the overall quality of Wikipedia compared to other encyclopedias, only the relative quality of user groups.
"We didn't evaluate content," she said, adding that Wikipedia is most valuable when used as a "first source" rather than a definitive authority.
Anthony pointed to the potential strengths of user-controlled communities. As the study points out, such communities allow for easier contributions and reduce participants' barriers to entry, improving the collective good.
Interest in the nature of contributors to Wikipedia has led Anthony and her colleagues to consider conducting new studies and writing further papers on the topic. One such possibility would be a review of Good Samaritans' IP addresses to gather their demographics, including whether they belong to particular businesses or colleges.
"To me it is still interesting to think about anonymous users, who they are and why they contribute," said Anthony.
