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 hav e to be addressed in the context of single user systems. The designer has t o take into account not only the interaction of a single user with the comp uter, but also the computer-supported interaction of several users with eac h other. In this article we describe the use of cooperation scenarios in th e design and evaluation of an innovative access control system for a concre te groupware application developed in the POLITeam project. We have used in formal textual scenarios to capture a rich description of the particulariti es of access to cooperatively used documents in three different organizatio ns. Based on these scenarios, we have developed an access control system, w hich not only allows specification of access rights in advance but also all ows involvement of third persons at the actual time of access, using negoti ation and notification mechanisms. We describe our evaluation strategy whic h again employs the cooperation scenarios developed in the empirical phase. After relating our approach to other work, we summarize and discuss our ex periences and the advantages land 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.