Originally answered Nov 6, 2017
(Image: Community of Practice elements according to Etienne Wenger-Trayner)
The most important elements of a community are:
- A compelling topic: The members and potential members must be passionate about the subject for collaboration, and it must be relevant to them.
- A critical mass of members: You usually need at least 100 members, with 200 being a better target. See this related discussion thread.
- A committed leader: The community leader should know the subject, have energy for stimulating collaboration, have sufficient time to devote to leadership, and then regularly spend time increasing membership, lining up speakers, hosting calls and meetings, asking and answering questions, and posting information which is useful to the members.