The goal of this work is to develop an approach to the design of on-line social environments. My thesis is that, in order to foster the development of vibrant and viable online communities, the environment - i.e. the technical infrastructure and user interface - must provide the means to communicate social cues and information: the participants must be able to perceive the social patterns of activity and affiliation and the community must be able to evolve a fluid and subtle cultural vocabulary.The theoretical foundation for the research is drawn from traditional studies of society and culture and from observations of contemporary on-line systems. Starting with an analysis of the fundamental differences between real and virtual societies - most notably, the presence and absence of the body - the first section examines the ways social cues are communicated in the real world, discusses the limits imposed on on-line communities due to their mediated and bodiless nature, and explores directions that virtual societies can take that are impossible for physical ones.
These ideas form the basis for the main part of the thesis, a design platform for creating sociable virtual environments. The focus of the discussion is on the analysis of a set of implemented design experiments that explore three areas of the platform: the visual representations of social phenomena, the role of information spaces as contexts for communication, and the presentation of self in the virtual world.