Parameters for Rhetorical Structure Theory Ontology1

Rhetorical Structure Theory (RST), a framework for analysing discourse structure above the clausal level, has been used extensively by both text analysts and researchers in text generation for the past decade. The proliferation of relations posited by various researchers using RST has highlighted an ontological problem with the theory: there have been no well-defined criteria determining which types of relations should belong within the frame-work, and what degree of granularity should be used to distinguish between these relations. Sanders, Spooren & Noordman (1992) have proposed the relational criterion as a criterion to perform this task. I examine the implications of applying their criterion to temporal relations, as a case study, and the implications the criterion may have for RST as a whole. 1. What is Rhetorical Structure Theory? This paper deals with the ontology of Rhetorical Structure Theory (RST) (Mann & Thompson (1987)—henceforth M&T). RST is a framework developed to account for text structure above the clause level; it does so by positing hierarchical relations between spans of text. It is used by linguists not only as a tool for analysing the structure of natural language text, but also as a planning aid in text generation—in particular, to help th