In a really large group or space, simply counting members, followers and visits might be enough, especially if the focus is mostly information dissemination. You could have a large number of lurkers and still have a very viable community. But in a small closed community of 15-20 people designed for collaboration, I would kinda expect there to be a pretty even distribution of activity across the members to call it engaged. So in the Jive 6 community reports I might look at a specific group or space's report and see:
- are the points on the user leader board reasonably distributed?
- is the daily activity fairly constant?
- on the adoption graph, is the number participating pretty close to the number active?
- on the People tab, are the recent activity dates for all the members fairly well clumped together?
Of course, with the CMRs in Jive 6 you have to go to each group or space and look at these numbers individually just for that place. It would be a lot harder to pick some of these metrics and run reports across the board to rank groups and spaces based on them, but if you are already doing custom metrics maybe you can do some things with them. For instance -- for the first bullet about well distributed points within a group or space, if you know the points for each member in a given place you could do something like convert those to a mean or median and standard deviation for each place and rank based on those.