A Discourse Model for Gist Preservation

Abstract

This paper describes an approach to gist preservation during automatic summarization whereby the source is a complex information structure which must be \pruned" and organized in such away astomake it appropriate for textual expression. Based on a discourse model, we propose a process whereby gist is guaranteed at the deep level according to communicative and rhetorical settings. In our approach the production of a coherent discourse structure of a summary incorporates both communicative goals and the inter-relationships between information units, allowing for discourse organization by progressively constraining planning decisions. The main function of such a goaldriven summarization model is thus to map intentions onto coherence relations whilst still observing the semantic dependency indicated by the message source. We describe a method for associating discourse relations at these three levels of representation-intentionality, coherence and semantics- in order to obtain summary message sources that highlight the central proposition of the discourse