Underspeciication in Discourse Structure and Semantics

1 Description theory Traditionally, grammars generate concrete data structures. Typically, these are trees whose nodes are labelled with syntactic and semantic information. However, a number of approaches have questioned this basic assumption arguing that grammars should manipulate more abstract structures namely descriptions of trees. In this paper, we show that a description-based approach is also useful in discourse, supporting the incremental construction of discourse structure for monologic discourse and the semantics to be associated with such structure. In the past, descriptions have been used for at least three distinct purposes in language processing. M.P.Marcus et al.1983] used tree descriptions for deterministic parsing. Crucially, these descriptions allow statements about dominance as opposed to immediate dominance. By permitting attachment to be underspeciied, descriptions avoid local attachment ambiguities. Instead of being committed to being the daughter of some existing node, an incoming constituent can be minimally restricted to being 1