Strategies for Sequencing as a Planning

The paper summarizes an ongoing investigation of the discourse planning tasks concerned with the se-quencing of utterances and their parts. Content selection provides some important constraints on sequencing, most notably those derived from the preconditions and eeects of planning operators. However these operators underconstrain sequencing, especially below the granularity at which they interface with a domain knowledge source. Further constraints are available from the integrative processes of the hearer or reader and from working memory limits. Application of these constraints is a matter for discourse planning because the choices relate to one's communicative goals. The planning task is one of translating functionally relevant relationships between units to be ordered into ordering constraints. A collection of strategies for this task are presented. Some of the strategies were used in an earlier implemented system; many are justiied by prior psycholinguistic research. Also discussed include current eeorts to extend the work to focus structure in general, and to address the handling of connicts between strategies.