From Predefined Consistency to User-Centered Emergent Consistency in Real-Time Collaborative Editing Systems

In this paper, we introduce a basic conceptual model of real-time collaborative editing systems which differentiates the coordination aspect of actions (which do not exist in single-user systems) from the application-dependent semantic aspect of actions (i.e., those actions that happen in single-user systems). Based on this model, a new taxonomy is provided to analyze the existing consistency-maintenance mechanisms and highlight potential new mechanisms. Furthermore, a new user-centered consistency model is proposed, which focuses on dynamic consistency that is negotiable among end users rather than static consistency that is automatically determined by the system. In the mean time, some challenging research issues in real-time collaborative editing systems are outlined