Conversationally relevant descriptions are definite descriptions that are not merely tools for the identification of a referent, but are also crucial to the discourse in other respects. I analyse the uses of such descriptions in assertions as conveying a particular type of conversational implicatures. Such implicatures can be represented within the framework of possible world semantics. The analysis is extended to non-assertive illocutionary acts on the one hand, and to indefinite descriptions on the other.

In this paper, I describe how Donnellan's distinction between referential and attributive uses of definite descriptions should be represebnted in a computational model of reference. After briefly discussing the significance of Donnellan's distinction, I reinterpret it as being three-tiered, relating to object representation, referring intentions, and choiceo of referring expression. I then present a cognitive model of referring, the components of which correspond to this analysis, and discuss the interaction that takes place among those components. Finally, the implementation of this model, now in progress, is described.