tailieunhanh - Báo cáo khoa học: "PLANNING NATURAL LANGUAGE EXPRESSIONS REFERRING"

This paper describes how a language-planning system can produce natural-language referring expressions that satisfy multiple goals. It describes a formal representation for reasoning about several agents' mutual knowledge using possible-worlds semantics and the general organization of a system that uses the formalism to reason about plans combining physical and linguistic actions at different levels of abstraction. It discusses the planning of concept activation actions that are realized by definite referring expressions in the planned utterances, and shows how it is possible to integrate physical actions for communicating intentions with linguistic actions, resulting in plans that include pointing as one. | PLANNING NATURAL LANGUAGE REFERRING EXPRESSIONS Douglas E. Appell SRI International Menlo Park California ABSTRACT This paper describes how a language-planning system can produce natural-language referring expressions that satisfy multiple goals. It describes a formal representation for reasoning about several agents mutual knowledge using possible-worlds semantics and the general organization of a system that uses the formalism to reason about plans combining physical and linguistic actions at different levels of abstraction. It discusses the planning of concept activation actions that are realized by definite referring expressions in the planned utterances and shows how it is possible to integrate physical actions for communicating intentions with linguistic actions resulting in plans that include pointing as one of the communicative actions available to the speaker. I. INTRODUCTION One of the most important constituent processes of natural-language generation is the production of referring expressions which occur in almost every utterance. Referring expressions often carry the burden of informing the hearer of propositions as well as referring to objects. Therefore many phenomena that are observed in dialogues Can- Figure 1 Satisfying Multiple Goals with a Referring Expression The author gratefully acknowledges the support for this research provided in part by the Office of Naval Research under contract N0014-80-C-0296 and in part by the National Science Foundation under grant MCS-8115105. not be explained by the simple view that referring expressions are descriptions of the intended referent sufficient to distinguish the referent from other objects in the domain or in focus. Consider the situation depicted in Figure 1 in which two agents an apprentice and an expert are cooperating on a common task such as disassembling an air compressor. Several tools are lying on the workbench and although the apprentice knows that the objects are there he may not necessarily