Elements of a Plan-Based Theory of Speech Acts

Abstract

This paper explores the truism that people think about what they say. It proposes hat, to satisfy their own goals, people often plan their speech acts to affect their listeners’ beliefs, goals, and emotional states. Such language use can be modelled by viewing speech acts as operators in a planning system, thus allowing both physical and speech acts to be integrated into plans.

Methodological issues of how speech acts should be defined in a plan-based theory are illustrated by defining operators for requesting and informing. Plans containing those operators are presented and comparisons are drawn with Searle’s formulation. The operators are shown to be inadequate since they cannot be composed to form questions (requests to inform) and multiparty requests (requests to request). By refining the operator definitions and by identifying some of the side effects of requesting, compositional adequacy is achieved. The solution leads to a metatheoretical principle for modelling speech acts as planning operators.

The research described herein was supported primarily by the National Research Council of Canada, and also by the National Institute of Education under Contract US-NIE-C-400-0116, the Department of Computer Science of the University of Toronto, and by a summer graduate student associateship (1975) to Cohen from the International Business Machines Corporation.