A Group-Based Time-Stamping Scheme for the Preservation of Group Intentions

A Multi-Versioning Scheme for Intention Preservation in Collaborative Editing Systems*

“…First, since the multi-version approach alone is not a complete solution to resolving conflicts in collaborative systems, other complementary mechanisms are necessary. For example, conflict control mechanisms such as the novel post-locking approach may be useful in controlling the proliferation of versions, and negotiation mechanisms or group intention preservation techniques (Xue et al 2002a) are necessary to support users to reach a group consensus. Second, usability studies need to be conducted to examine how the multi-versioning technique will support or hinder collaborative editing processes.…”

“…The execution effect is that no conflicting operations are applied to the same version. This is the multi-version approach proposed in the Tivoli (Moran et al 1995) and GRACE (Chen and Sun 1999;Sun and Chen 2002) systems, which can be characterized as computer supported conflict resolution by human users (Xue et al 2002a).…”

“…Main document is the document under collaborative editing, and branch document is for storing the versions created due to conflicts such that the multi-versioning effect will not interfere with the main document. All the versions created for one object in conflict are presented in one branch document, whereas versions created for different objects in conflict are kept in different branch documents (Xue et al 2002a).…”

“…In group editors, a direct consequence of unconstrained editing is intention violation due to concurrent executions of operations, e.g., one intention may be overwritten or changed by another. Therefore, intention preservation is an important aspect of consistency maintenance in group editing systems (Munson and Dewan 1996;Sun and Ellis 1998;Chen and Sun 1999;Prakash 1999;Xue at al. 2002a;Xue 2002).…”

“…Since it is generally infeasible for the systems to have the knowledge necessary to properly resolve conflicts among users, the systems must be capable of reflecting all aspects of human conflict and cooperation and facilitating human users in conflict resolution. To put it in another way, the systems must preserve individual users' intentions (represented by the operations they issue) that may be conflicting with each other, and provide facilities to help users reach a consensus, or group intention (Xue et al 2002a). The challenge we face is how to maintain the unconstrained multi-user editing process such that all replicas (or copies) of the document converge (become identical) while each user's intentions are preserved.…”