The use of cooperation scenarios in the design and evaluation of a CSCW system

Design and evaluation of groupware systems raise questions which do not have to be addressed in the context of single user systems. The designer has to take into account not only the interaction of a single user with the computer, but also the computer-supported interaction of several users with each other. In this article we describe the use of cooperation scenarios in the design and evaluation of an innovative access control system for a concrete groupware application developed in the PoLITeam project. We have used informal textual scenarios to capture a rich description of the particularities of access to cooperatively used documents in three different organizations. Based on these scenarios, we have developed an access control system, which not only allows specification of access rights in advance but also allows involvement of third persons at the actual time of access, using negotiation and notification mechanisms. We describe our evaluation strategy which again employs the cooperation scenarios developed in the empirical phase. After relating our approach to other work, we summarize and discuss our experiences and the advantages (and disadvantages) of using scenarios for the design and evaluation of computer systems cooperative work (CSCW) systems. Finally, we give a brief outlook on future work