Design and implementation of action history view mechanisms for hypermedia systems

For computer-supported cooperative work (CSCW), it is very important to understand the activities of users in a group. To support this understanding, we propose a mechanism called an "action history view" which shows the past actions of a user to other users for the purpose of letting them know what he/she has done, without revealing secret or useless information. The mechanism is coordinated among users who are distributed in terms of time. In this paper, the concept of the action history view mechanism is applied to hypermedia systems based on an object-oriented model to support users in viewing or reviewing past presentations in a short amount of time in hiding specified actions which it is not appropriate to show to other users. The generation of views is executed by removing a series of actions that correspond with the component to be hidden. The system also has a function for supporting users to select actions interactively while the user is viewing the replay. To qualify those kinds of views, the actions performed in a presentation are recorded in an action history stream, which consists of multiple logs. Finally, the application and implementation of a prototype of the action history view mechanism to a distance education system based on hypermedia is described.