Local And Global Structures In Discourse Understanding

We are interested in the nature of content structures in terms of which it would be possible to account for reasoning processes in understanding natural language texts. One of the most crucial problems here at the present time is: how and by which mechanisms these reasoning processes are controlled and directed. As the emphasis in the design of discourse understanding systems so far has been on the problems of knowledge organization and representation, we are only beginning to guess what the corresponding processing mechanisms are and how they function, although an increasing number of papers has been devoted to these problems as well. There are studies of the relation of understanding to such types of knowledge processing as problem solving and planning (e.g., Black and Bower 1980, Wilensky 1981). Various types of content units and structures needed to account for knowledge processing have been proposed in the general context of modeling discourse understanding (e.g., Allen 1981; Cohen 1981; Dyer 1982; Wilensky 1980). We ourselves have discussed an approach to knowledge units and processing mechanisms in questions, as a part of a computer system which understands stories of a certain kind (Litvak et al. 1981), as well as on a more theoretical level (Oim 1980).