ISSUQS in Natural Language Communication

Two premises, reflected in the title, underlie the perspective from which I will consider research in natural language processing in this paper.* First, progress on building computer systems that process natural languages in any meaningful sense (i.e., systems that interact reasonably with people in natural language) requires considering language as part of a larger communicative situation. In this larger situation, the participants in a conversation and their states of mind are as important to the interpretation of an utterance as the linguistic expressions from which it is formed. A central concern when language is considered as communication is its function in building and using shared models of the world. Indeed, the notion of a shared model is inherent in the word “communicate,” which is derived from the Latin communicare, “to make common.” Second, as the phrase “utterance and objective” suggests, regarding language as communication requires consideration of what is said literally, what is intended, and the relationship between the two. Recently, the emphasis in research in natural language processing has begun to shift from an analysis of utterances as isolated linguistic phenomena to a consideration of how people use utterances to achieve certain objectives. But, in considering objectives, it is important not to ignore the utterances themselves. A consideration of a speaker’s underlying goals and motivations is critical, but so is an analysis of the particular way in which that speaker expresses his thoughts. (I will use “speaker” and “hearer” to refer respectively to the producer of an utterance and the interpreter of that utterance. Although the particular communicative environment constrains the set of linguistic and nonlinguistic devices a speaker may use (Rubin, 1977), I will ignore the differences and concentrate on those problems that are common across environments.) The choice of expression has implications for such things as what other entities may be discussed in the ensuing discourse, what the speaker’s underlying beliefs (including his beliefs about the hearer) are, and what social relationship the speaker and hearer have. The reason for conjoining “utterance” and