d238a290_n__Communities___Collaboration__Sociability_Concerns
[User Questions] 2. How do I join or leave? [Usability Concerns] Are the instructions for registering clear? Is it a short procedure? Is there a statement ensuring privacy and security? [Sociability Concerns] 
Should this be an open or a closed community? How sensitive are the issues and participants? Do we want to control who joins?
CoP Usability and Sociability Heuristics | Curation, Communities & Collaboration
Sociability Concerns