| As computers become widely used and the network grows rapidly, there has been a growing interest in collaborative systems that allow people to interact and work together over the network. A key to success of a collaborative system is to enable people to collaborate in a manner best suited to their needs. However, there are two major obstacles in achieving this. One is new unexpected needs in a collaborative environment and the other is different group needs in a user community using a collaborative system. To address these, this thesis presents Collaboratory Builder's Environment (CBE), a software infrastructure for building flexible, Internet-based collaborative environments that can be tailored to meet a range of collaborative needs. CBE is based on the metaphor of a room representing a shared workspace, which contains users, group-aware applets and arbitrary data objects. The contributions of CBE are as follows. First, it provides extensible collaborative environment that allows newly-developed tools to be incorporated into the system. Second, it provides dynamic collaborative environment for users. A user can set up shared workspaces by creating new objects (e.g. URLs, group works, uploaded files) or by bring objects from other shared workspaces. A user is allowed to participate in multiple shared workspaces at the same time. Finally, a shared workspace can be customized to support different collaboration paradigms (e.g. rooms, call centers). The persistence of shared workspace state across synchronous sessions allows shared workspaces to be used for asynchronous collaboration as well as synchronous group tasks. CBE supports role-based access control that facilitates open access over the Web to a collaboratory. A prototype of the model has been implemented in Java and used extensively in several world-wide scientific campaigns by space scientists over the Internet. Through the analysis of traced usage data, we identify users' usage behavior in actual collaborations and discuss the effectiveness of our model. |
