An analysis of agent speech acts as institutional actions

All major proposals in the field of Agent Communication Languages deal with agent communication in terms of speech acts. This choice is important not only because it allows one to rely on a powerful and deep theory of communication, namely Speech Act Theory, but also because AI has developed computationally effective ways of dealing with actions. However, the AI literature does not seem to distinguish between "physical" or "natural" actions and speech acts in a principled way. This attitude often results in a fairly confused and inadequate account of what it means that an agent performs a speech act - a situation that is likely to hinder further developments in the field of Agent Communication Languages. In this paper we analyze the concept of speech act, and point out the main differences between speech acts, conceived as a special category of "institutional" actions, and natural actions. On the basis of our analysis, we conclude that speech acts should be modelled in terms of the specific social effects brought about by their performance.