Introduction

This chapter discusses the problems of planning surface linguistic actions, including surface speech acts, concept activation actions, and focusing actions. What distinguishes these surface linguistic acts from the illocutionary acts considered in Chapter 5 is that they correspond directly to parts of the utterance that are produced by the planning agent. An agent intends to convey a proposition by performing an illocutionary act. There may be many choices available to him for the purpose of conveying the proposition with the intended illocutionary force. For example, he may make a direct request by using an imperative, or perform the act of requesting indirectly by asking a question. He usually has many options available to him for referring to objects in the world.

A surface linguistic act, on the other hand, represents a particular linguistic realization of the intended illocutionary act. Planning a surface speech act entails making choices about the many options that are left open by a high-level specification of an illocutionary act. In addition, the surface speech act must satisfy a multitude of constraints imposed by the grammar of the language. The domain of reasoning done by the planner includes actions along with their preconditions and effects. The grammatical constraints lie outside this domain of actions and goals (excluding, of course, the implicit goal of producing coherent English), and are therefore most suitably specified within a different system.