Communities in BSCW allow large groups of users to access workspaces with equal access rights without sacrificing consistent performance. Communities are also suitable as self-organized forums for users with similar interests.
In the following example cases, one would choose a community in BSCW.
•You want to create a forum for all hobby astronomers who are users of your BSCW server. This should be a workspace that is announced to the users of your BSCW server and to which all users may gain access to read the content and also post relevant documents and references ("astronomy forum").
•You want to create a workspace for all 250 members of a tab in your organization, where you and some other managers can post documents, references and whole subfolders that represent useful information for the whole tab ("bulletin board").
•You manage a workspace whose number of members has grown very strongly over time. As a result, the server's response times have become unsatisfactory even for simple operations on the workspace ("Crowded workspace").
A community is a group of users, its members. Each community is a member of exactly one workspace, the community workspace, which is also called the associated workspace of the community. A workspace can have at most one community as a member, i.e. there is a one-to-one relationship between a community and its workspace. Community members can access the community workspace in a single role, the Community Role (not to be confused with the role that community members hold in relation to the community itself this is the Member role, which is set for communities with minimal rights). The managers of the community workspace are also the managers of the community.
Note that accessing a workspace through a community with many members in a single role is significantly superior in terms of performance to accessing the same workspace by the same number of members in different roles, each with different access rights. Communities can be treated as a single user in many contexts, which significantly reduces the overhead of calculating access rights.
Communities differ in terms of their recording rules and visibility to other users:
•Open communities are visible to all registered users of your BSCW server, and users may become members by themselves by joining the community.
•Closed communities are visible to all registered users of your BSCW server, but users cannot become members on their own, they have to ask the community managers to join.
•Hidden communities are not visible to the users of your BSCW server. You may become a member of a hidden community only by invitation of a community manager.
Open and closed communities can be invited to other communities, hidden communities cannot. The same applies to the member groups of community workspaces with regard to invitations to other workspaces.