The last chapter focused on a formal description of cooperation leaving aside the human and social aspects. In the center of this chapter is computer support of human communication as it has been the scope of traditional CSCW and Groupware while agent based cooperation will be left to the following chapter. Lots of efforts have been made to categorize CSCW systems according to taxonomy criteria. The most common taxonomy uses the famous same/different time/place criteria. It was later extended to a three-by-three matrix by [1] who included different-but-predictable and different-but-unpredictable attributes for time and place. Other approaches start with the persons who cooperate and the information they share.
Here, two main aspects for categorizing CSCW systems, namely the explicit and the implicit interaction will be presented. The first one refers to direct communication between humans while the latter one focuses on the object of common interest (see Figure 1). The two following sections will get into more detail of these main categories. A comprehensive taxonomic description of the CSCW can be found in [2] and [3].