User population and user contributions to virtual publics: A systems model

This paper provides a comprehensive review of empirical research into user contributions to computer-mediated discourse in public cyber-spaces, referred to here as virtual publics. This review is used to build a systems model of such discourse. The major components of the model are i) critical mass, ii) social loafing, and iii) the collective impact of individual cognitive constraints on the processing of group messages. By drawing these three components into a single model it becomes possible to describe the shape of a `user-contributions/user-population function' after controlling for context. Virtual publics can be created with the support of various technologies including email, newsgroups, web-based bulletin boards etc. Traditionally the choice of technology platform and the way it is used has largely depended on arbitrary factors. This paper suggests that choices of this nature can be based on knowledge about required segmentation points for discourse as they relate to a particular type of technology. This is because the `user-contributions/user-population function' will map differently to different classes of technology. Similarly the different classes of technologies used to enable virtual publics will each have different stress zones at which users will experience information overload resulting from computer mediated discourse.