CSCW research has had problems in selecting the basic structural and functional unit for the analysis of work. For convenient location of the computer support, some meaningful intermediate whole should be defined between the individual and the organization. The concepts of 'team' and 'group' are intuitively understandable, but somewhat weak for serious analysis.

This paper suggests that the concept of 'activity' from Activity Theory could fill the gap, and compares the properties of the activity concept with the needs of CSCW research. A classification of work support types based on the concept of activity, is produced in order to demonstrate its potential usefulness.