[3sixty]

This is a good question. Here is my take on it.

bb forums are enclosed, stand-alone, old-school discussion boards that are traditionally organized according to “freshness” (ie, who commented last), which is supposed to tell you what threads are most active.

The activity stream is where it gets confusing. It is supposed to capture activity chronologically, regardless of where it happens in the group. So in the activity stream you will see forum posts, forum replies, group wire posts, and status notifications like “so-and-so just joined this group.” It gets blurry because you can also comment on activity stream items… so it’s not just a stream of activity, but another method for interacting.

In my limited experience, it is a little confusing to have both the activity stream and forum running at the same time. It’s especially confusing because by default, you can have a forum discussions ongoing, and have a parallel but completely separate discussion on the SAME posts in the activity stream. This can be disabled in the BuddyPress settings, but in my opinion, this should be off by default.