Beyond the Whiteboard: synchronous collaboration in shared object spaces

Synchronous collaboration via a network of distributed workstations requires concurrency awareness within a relaxed WYSIWIS model (What You See is What I See). Many applications let users navigate within highly structured object spaces, such as documents, multimedia courses, graphs, or nested tables, which can be distributed asynchronously. To support their manipulation through distributed teams, we provide a novel interaction paradigm, called finger. A finger serves to highlight objects of interest within the shared object space. Locations of fingers, their movements, and changes inflicted on objects can be signaled by means of operation broadcasting to other collaborators who need to be aware of it. Other than telepointers, fingers do not require window-sharing and are independent of the actual object presentation. This paper describes the interaction paradigm and basic set of operations. It uses a tele-teaching scenario to illustrate its features. However its collaboration principles apply to many other CSCW areas, like shared authoring, trading, scheduling, crisis management, and distance maintenance