Perrault, C. R.

A plan-based analysis of indirect speech acts


It proposes that, to satisfy their own goals, people often plan their speech acts to affect their listeners' beliefs, goals, and emotional states. Methodological issues of how speech acts should be defined in a plan-based theory are illustrated by defining operators for requesting and informing. The operators are shown to be inadequate since they cannot be composed to form questions (requests to inform) and multiparty requests (requests to request). The solution leads to a metatheoretical principle for modelling speech acts as planning operators.

Analyzing intention in utterances


This paper describes a model of cooperative behavior and describes how such a model can be applied in a natural language understanding system. We assume that agents attempt to recognize the plans of other agents and, then, use this plan when deciding what response to make. In particular, we show that, given a setting in which purposeful dialogues occur, this model can account for responses that provide more information that explicitly requested and for appropriate responses to both short sentence fragments and indirect speech acts.

Elements of a plan-based theory of speech acts


Formal descriptions of plans typically treat actions as operators, which are defined in terms of applicability conditions, called preconditions, effects that will be obtained when the corresponding actions are executed, and bodies that describe the means by which the effects are achieved. As an illustration of this approach, this paper presents a simple planning system, defines the speech acts of requesting and informing as operators within that system, and develops plans containing direct requests, informs and questions (which are requests to inform). We argue that a plan-based theory, unlike other proposed theories of speech acts, provides formal adequacy criteria for speech act definitions: given an initial set of beliefs and goals, the speech act operator definitions and plan construction inferences should lead to the generation of plans for those speech acts that a person could issue appropriately under the same circumstances.3 This adequacy criterion should be used in judging whether speech act definitions pass certain tests, in particular, the test of compositionality. Another goal of this research is to develop metatheoretical principles that state how to formulate speech act definitions to pass these adequacy tests.