this paper examines these relationships in more detail, and asks whether contributions, perceived benefits, and the relationships among them were different for owners of the lists (formal leaders), active posters, and lurkers of the groups, and for nonwork-related and work related groups. To test our hypotheses, we conducted repeated measures ANOVAs with respondent role (owner or other member) and group type (non-work or work-related) as fixed effects, and group size and content volume as...