Speech acts, commitment and multi-agent communication

Abstract

The principle aim of this paper is to reconsider the suitability of Austin and Searle's Speech Act theory as a basis for agent communication languages. Two distinct computational interpretations of speech acts are considered: the standard "mentalistic" approach associated with the work of Cohen and Levesque which involves attributing beliefs and intentions to artificial agents, and the "social semantics" approach originating (in the context of MAS) with Singh which aims to model commitments that agents undertake as a consequence of communicative actions. Modifications and extensions are proposed to current commitment-based analyses, drawing on recent philosophical studies by Brandom, Habermas and Heath. A case is made for adopting Brandom's framework of normative pragmatics, modelling dialogue states as deontic scoreboards which keep track of commitments and entitlements that speakers acknowledge and hearers attribute to other interlocutors. The paper concludes by outlining an update semantics and protocol for selected locutions.