Is it sometime difficult for you to find the "perfect" feed in a community focussing exactly on the item you want to track, with the good granularity? If your response is yes, this presentation is for you!
8. Observer Service Like the human visual system providing a way to focus only on a subpart of what a human actually views, the observer service allows a user (or an agent) to focus his perception on a certain aspect of the activity of the community according to his intentions.