1.      Introduction

This paper is an investigation into patterns of interaction in synchronous, text-based computer-mediated communication (henceforth SCMC). As with much CMC research, the underlying aim is to contribute to an understanding of the extent to which human interaction is affected by mediation via computers.

The primary motivation for the paper is the recognition of the tendency in multi-participant SCMC discourse for certain notable patterns of interaction ? conversational floors ? to develop. Ultimately the question is addressed as to what factors account for such patterns. In so doing, reference is made to research into multi-party conversation in both the written and spoken mode.

The paper starts with a description of the source of the data, and a comment on the analysis of SCMC discourse. In the following section SCMC is discussed in relation to the fundamental concepts of cohesion and coherence in discourse. Then an approach to cohesion in SCMC, the conversational floor, is described; its elements are outlined, and some of its various manifestations in the discourse text are exemplified. Finally we turn to aspects of the discourse which influence the development of floors: the role relations of the participants; the communicative action and the topic of the discourse; and certain medium-related factors. Their influence is discussed with reference to an extended stretch of SCMC text tracing the development of conversational floors.