Design Considerations in Choosing Operations for Building Groupware Systems

We have implemented a prototype toolkit, called DistEdit, for building interactive group editors in distributed environments. The toolkit allows different editors (e.g., vi, Emacs) to be used in the same group session. Based on our experience in building the toolkit, we report here some design solutions that are commonly used in single-user editors, but may not necessarily be appropriate in group editors. Furthermore, design of group editors requires a better understanding of the semantics of editing operations than in the corresponding single-user editors. These semantics are useful for providing a variety of services, such as undo, concurrency control, and selective replay. Finally, we point out that implementing high-level actions is much more complex in group editors than in single-user editors because high-level actions may need to be implemented as a transaction to guarantee correct user-level semantics. This position paper is presented in the context of text editors; however, ma..