In command-line interfaces users were required to know computer terminology, concepts, and syntax in order to accomplish their tasks. Current user interfaces exploit visual metaphors of physical objects, such as a desktop and folders. Applications are confined to overlapping rectangular windows on the desktop, similar to their physical counterparts (papers, calendar, calculator, etc.) However, these interfaces have not kept pace with user demands because they provide no added value over their problematic traditional physical counterparts . Physical metaphors can be limiting in terms of interaction and screen utilization.
Novel approaches emphasize a docu-centric approach (Microsoft OLE) in which documents become more important and applications fade into the background. Users' focus are on multimedia documents which contains information pieces of various formats. However, these approaches lack an effective scalable organization method.
Although these innovations are one step to achieve a visual environment in harmony with users' perceptions of their work, an effective organization of information according to users' roles that reflects this perception is needed[8, 9]. A great deal of personal organization is required to manage multiple roles whose goals, partners, tools, and documents are likely to be very different. When users are working on their tasks they should find related people, documents, and tools rapidly. Users should be able to create, abandon, extend, and modify the current role hierarchy.