My guess is that the life cycle of online mailing lists as described in that outline ( http://www.rider.edu/users/suler/psycyber/lifelist.html) apply to many online groups. There may be some variations depending on the people in the group, the purpose of the group, and the software environment... but I think most groups (in-person and online) tend to follow the general pattern of group development: the norming, conforming, storming, and performing stages.