Defense Mechanism or Socialization Tactic? Improving Wikipedia's Notifications to Rejected Contributors

Unlike traditional firms, open collaborative systems rely on volunteers to operate, and many communities struggle to maintain enough contributors to ensure the quality and quantity of content. However, Wikipedia has historically faced the exact opposite problem: too much participation, particularly from users who, knowingly or not, do not share the same norms as veteran Wikipedians. During its period of exponential growth, the Wikipedian community developed specialized socio technical defense mechanisms to protect itself from the negatives of massive participation: spam, vandalism, falsehoods, and other damage. Yet recently, Wikipedia has faced a number of high profile issues with recruiting and retaining new contributors. In this paper, we first illustrate and describe the various de fense mechanisms at work in Wikipedia, which we hypothe size are inhibiting newcomer retention. Next, we present re sults from an experiment aimed at increasing both the quan tity and quality of editors by altering various elements of these defense mechanisms, specifically pre scripted warn ings and notifications that are sent to new editors upon re verting or rejecting contributions. Using regression models of new user activity, we show which tactics work best for different populations of users based on their motivations when joining Wikipedia. In particular, we found that per sonalized messages in which Wikipedians identified them selves in active voice and took direct responsibility for re jecting an editor’s contributions were much more successful across a variety of outcome metrics than the current mes sages, which typically use an institutional and passive voice.