Identity and bond theories to understand design decisions for online communities

When we develop systems and policies for online communities, we make design decisions that may appeal to some members but discourage others. In this article, we examine online community design decisions in light of the common identity and common bond theories from social psychology. These theories posit two kinds of attachment to online groups - attachment to the group as a whole (group identity) and attachment to individual group members (member bonds). We review literature on the antecedents of group identity (social categorization, in-group interdependence, and out-group presence) and member bonds (social interaction, personal knowledge, and interpersonal similarity), and convergent and divergent consequences of the two types of attachment. We discuss implications of these antecedents and consequences for critical design tradeoffs, such as those associated with constraining or promoting off-topic discussion, requiring authentication or allowing anonymity, limiting group size or allowing uncontrolled growth, and structuring content or leaving it unstructured.