John Riedl- The Effects of Diversity on Productivity, Member Withdrawal, and Decision Quality in a Social Production Community

The "wisdom of crowds" argument emphasizes the importance of diversity in online collaborations, such as open source projects and Wikipedia. However, decades of research on diversity in offline work groups have painted an inconclusive picture. On the one hand, the broader range of insights from a diverse group can lead to improved outcomes. On the other hand, individual differences can lead to conflict and diminished performance. We examine the effects of group diversity on the amount of work accomplished and on member withdrawal behaviors in the context of WikiProjects. We find that increased diversity in experience with Wikipedia increases group productivity and decreases member withdrawal -- up to a point. We also look at the effectiveness of these groups at making collective decisions in the presence of disagreement. We examined over 100,000 decisions made by small working groups in Wikipedia, and analyzed how decision quality in these online groups is influenced by four group composition factors: the size of the group, how members were invited to the group, the prior experience of group members, and apparent bias shown by the group administrator. Our findings lead us to recommendations for designers of social production communities.