In Relevance: Communication and Cognition, we outline a new approach to the study of human communication, one based on a general view of human cognition. Attention and thought processes, we argue, automatically turn toward information that seems relevant: that is, capable of yielding cognitive effects – the more, and the more economically, the greater the relevance. We analyse both the nature ofcognitive effects and the inferential processes by which they are derived.

Communication can be achieved by two different means: by encoding and decoding messages or by providing evidence for an intended inference about the communicator's informative intention. Verbal communication, we argue, exploits both types of process. The linguistic meaning of an utterance, recovered by specialised decoding processes, serves as the input to unspecialised central inferential processes by which the speaker's intentions are recognised.

Fundamental to our account of inferential communication is the fact that to communicate is to claimsomeone's attention, and hence to imply that the information communicated is relevant. We call this idea, that communicated information comes with a guarantee of relevance, the principle of relevance. We show that every utterance has at most a single interpretation consistent with the principle of relevance, which is thus enough on its own to account for the interaction of linguistic meaning with contextual factors in disambiguation, reference assignment, the recovery of implicatures, the interpretation ofmetaphor and irony, the recovery of illocutionary force, and other linguistically underdetermined aspects of utterance interpretation.