This paper discusses theory and concepts in designing a synchronous shared workspace to support human interaction, and a description of such a system. The Amsterdam Conversation Environment (ACE) supports group interaction in faceto-face meetings. ACE does not, however, support meeting process; instead it is designed to support conversation and stimulate interaction among group participants. The ACE design emerges from design conversations seeded with several specific concepts. One is the notion of semi-structured computer applications, which leave room for the development, by users, of group conventions to structure how the group interfaces with the computer support environment. A related topic is the difficulty of setting "support" boundaries: what should the machine do or enable vs what are the structure and function responsibilities of user group members themselves? Another concept is the development of user-languages as a reflection of group experience and coherence. A third concept is the transition away from group-member equivalence within computer-mediated conversation (a currently favored view in the design of "democratic" computer systems) toward encouraging variety and stimulating "next actions" among users. Using these and other concepts, we create an overall conceptual picture of what ACE does, how it feels, and how the user interface looks and works, which we call the "design image". We conclude with some thoughts about the next steps in the project. © 1991.
