tailieunhanh - Báo cáo khoa học: "A Practical Nonmonotonic Theory for Reasoning about Speech Acts"

A prerequisite to a theory of the way agents understand speech acts is a theory of how their beliefs and intentions are revised as a consequence of events. This process of attitude revision is an interesting domain for the application of nonmonotonic reasoning because speech acts have a conventional aspect that is readily represented by defaults, but that interacts with an agent's beliefs and intentions in many complex ways that may override the defaults. Perrault has developed a theory of speech acts, based on Rieter's default logic, that captures the conventional aspect; it does not, however, adequately account for. | A Practical Nonmonotonic Theory for Reasoning about speech Acts Douglas Appelt Kurt Konolige Artificial Intelligence Center and Center for the Study of Language and Information SRI International Menlo Park California Abstract A prerequisite to a theory of the way agents understand speech acts is a theory of how their beliefs and intentions are revised as a consequence of events. This process of attitude revision is an interesting domain for the application of nonmonotonic reasoning because speech acts have a conventional aspect that is readily represented by defaults but that interacts with an agent s beliefs and intentions in many complex ways that may override the defaults. Perrault has developed a theory of speech acts based on Rieter s default logic that captures the conventional aspect it does not however adequately account for certain easily observed facts about attitude revision resulting from speech acts. A natural theory of attitude revision seems to require a method of stating preferences among competing defaults. We present here a speech act theory formalized in hierarchic autoepistemic logic a refinement of Moore s autoepistemic logic in which revision of both the speaker s and hearer s attitudes can be adequately described. As a collateral benefit efficient automatic reasoning methods for the formalism exist. The theory has been implemented and is now being employed by an utterance-planning system. 1 Introduction The general idea of utterance planning has been at the focus of much NL processing research for the last ten years. The central thesis of this approach is that utterances are actions that are planned to satisfy particular speaker goals. This has led researchers to formalize speech acts in a way that would permit them to be used as operators in a planning system 1 2 . The central problem in formalizing speech acts is to correctly capture the pertinent facts about the revision of the speaker s and hearer s attitudes that ensues as a consequence