I have to find this paper :
Spatial model of awareness
[Viller, 1999 #397] see [Cockburn, 1999 #76] for review
Benford, S., C. Brown, et al. (1996). Shared spaces: Transportation, artificiality, and spatiality. Proceedings of the ACM CSCW ’96 Conference on Computer Supported Cooperative Work, New York, Association for Computing Machinery.