The Decline of Wikipedia
Halfaker’s study, which he conducted with a Minnesota colleague and researchers from the University of California, Berkeley, and the University of Washington, analyzed Wikipedia’s public activity logs. The results paint a numerical picture of a community dominated by bureaucracy. Since 2007, when the new controls began to bite, the likelihood of a new participant’s edit being immediately deleted has steadily climbed. Over the same period, the proportion of those deletions made by automated tools rather than humans grew. Unsurprisingly, the data also indicate that well-intentioned newcomers are far less likely to still be editing Wikipedia two months after their first try.
In their paper on those findings, the researchers suggest updating Wikipedia’s motto, “The encyclopedia that anyone can edit.” Their version reads: “The encyclopedia that anyone who understands the norms, socializes him or herself, dodges the impersonal wall of semi-automated rejection and still wants to voluntarily contribute his or her time and energy can edit.”
Update (2013-10-31): See also the Hacker News discussion.