symbolic indication of presence, it should allow to perceive the different activity levels of the actors, i.e. their availability and reachability, and their actual engagement in the cooperation process. In addition, means may be provided which enable a partner to actively and explicitly articulate her presence with dedicated symbolic gestures and thus attracting the others attention.
Both, personalised and also anonymous indication of presence should be provided. Sometimes it is sufficient to recognise that someone is present or how many people are present. In other cases it is necessary to identify or even authenticate those people. The symbolic indication of presence should provide for any of these awareness levels.
A challenging task is the development of adequate techniques for the symbolic representation of people and their actions ( McGrath, 1998) in environments constituted from real world and virtual world locations. Real world events may be indicated in virtual worlds and vice versa. This will allow to overcome the separation between pure real and virtual worlds and enable social contacts across both environments.
While iconic representations are rather used to provide asynchronous awareness, we use 3D visualization for the representation of social presence in a context specific or spatial sense. The use of a 3D interface allows us to handle a large number of complex events by presenting them in a condensed, highly descriptive and informative way. In our approach the spatial arrangement of the virtual world represents physical places like a coffee room as well as context specific locations, such as a virtual BSCW shared workspace ( Bentley, et al., 1997).