Intentionality in a Topical Approach of Discourse Structure

The alternative to be outlined provides a proposal to solve a central problem in research on discourse structure and discourse coherence, namely, as pointed out by many authors, that of the relationship between linguistic and intentional structure, or, in other words, between subject matter and presentational relations (Mann and Thompson 1988) or informational and intentional relations (Moore and Pollack 1992). As is argued for in Van Kuppevelt (1993), this alternative not only implies uniformity on the structural levels involved, i.e. the linguistic and intentional level, but also on the level of attentional states (Grosz and Sidner 1986). 2 The latter is ruled by the dynamics of topic constitution and topic termination, determining which discourse units are in focus of attention during the development of the discourse. 3 We will see that both linguistic relations and intentions are defined in a uniform way by topic-forming questions in discourse, thereby automatically satisfying the need for a multi-level analysis as is argued for in Moore and Paris (1992), and as is signalled by Dale (this volume), avoiding differences in discourse segmentation between RST analyses and intentional approaches. The central hypothesis underlying this alternative is that the structural coherence in discourse is governed by the discourse-internal process of questioning, consisting of the contextual induction of explicit and/or implicit topic-forming questions. This process gives rise to the phenomenon that the organization of discourse segments (as well as the associated isomorphic structure of intentions) agrees with the internal topic-comment structure, and that in the following specific way: (i) every discourse unit u(D)Tp has associated with it a topic Tp (or, a discourse topic DTp) which is provided by the (set of) topic-forming question(s) Qp that UTp has answered, and (ii), the relation between discourse units u(D) Ti is determined by the relation between the topic-forming questions Qi answered by these discourse units u(D)Ti. 4 Topics are thus context-dependently characterized in terms of questions arising from the preceding discourse. As is elaborated upon in Van Kuppevelt (1991/92) every contextually induced explicit . . . . or implicit (sub)question Qp that . . . . . . is answered in discourse constitutes a (sub)topic Tp. Tp ts that which ts questioned; an undetermined set of (possibly non-existent) discourse entitles (or a set of ordered n-tuples of such entities in the case of an n-fold question) which needs further