An academic study combining editing data with page view logs has added some new understanding about the quality and authorship of Wikipedia content. It concluded that frequent editors have the most impact on what Wikipedia readers see, while the effect of vandalism is small but still a matter of growing concern.
The results of the study are reported in a paper titled "Creating, Destroying, and Restoring Value in Wikipedia" (available in PDF), to be published in the GROUP 2007 conference proceedings. It was put together by a research group in the University of Minnesota department of computer science and engineering. Based on sampled data provided by the Wikimedia Foundation, showing every tenth HTTP request over a one-month period, they created a tool for estimating the page views for a Wikipedia article during a given timeframe.
In the absence of this type of data, previous studies have largely relied on an article's edit history for analysis. Interestingly, the study concluded that there is "essentially no correlation between views and edits in the request logs."
The study estimated a probability of less than one-half percent (0.0037) that the typical viewing of a Wikipedia article would find it in a damaged state. However, the chances of encountering vandalism on a typical page view seem to be increasing over time, although the authors identified a break in the trend around June 2006, late in the study period. They attributed this to the increased use of vandalism-repair bots.