Inquiry Semantics: A Functional Semantics of Natural Language Grammar

Inquiry Semantics: A Functional Semantics of Natural Language Grammar 1 William C. Mann USC/Information Sciences Institute 4676 Admiralty Way Marina del Rey, California 90292 USA Summary Programming a computer to operate to a significant degree as an author is a challenging research task. The creation of fluent multiparagraph text is a complex process because knowledge must be expressed in linguistic forms at several levels of organization, including paragraphs, sentences and words, each of which involves its own kinds of complexity. Accommodating this natural complexity is a difficult design problem. To solve it we must separate the various relevant kinds of knowledge into nearly independent collections, factoring the problem. Inquiry semantics is a new factoring of the text generation problem. It is novel in that it provides a distinct semantics for the grammar, independent of world knowledge, discourse knowledge, text plans and the lexicon, but appropriately linked to each. It has been implemented as part of the Nigel text generation grammar of English. This paper characterizes inquiry semantics, shows how it factors text generation, and describes its exemplification in NigeL The resulting description of inquiries for English has three dimensions: the varieties of operations on information, the varieties of information operated upon, and the subject matter of the operations. The definition framework for inquiries involves both traditional and nontraditional linguistic abstractions, spanning the knowledge to be represented and the plans required for presenting it. 1 Introduction Text generation is the generation of language to conform to an a priori intention and plan to communicate. The problem of text generation is naturally complex, requiring the 1previous title: Generating Text: Knowledge a Grammar Demands. This research was SUl~ported by the Air Force Office of Scientific Research contract No, F49620-79-C-0181. The views and conclusions contained in this document are those of the author and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Ihe Air Force Office of Scientific Research of the U.S Government. active coordination of many kinds of knowledge having independent origins and character. A significant part of this complexity is in grammatical knowledge. It is important for the grammar of a text generator to have its own integrity, yet without being operationally autonomous. 2 The methods of generating text presented here grew out of a concern to maintain the integrity and definitional independence of particular existing fragments of grammar. These methods employ the grammar in ways which do not make any strong assumptions about the nongrammatical kinds of knowledge in the text generator. They control the use of the grammar in generation. We-first describe the methods, showing how they make grammatical generation possible. Then we show how they factor the problem of text generation and clarify the role of knowledge representations. Finally we characterize inquiry semantics and the notion of meaning. 2 Grammar and Control People often anticipate that a text generator will plan the operations of the grammar in full detail and then execute such plans. In fact, such a mode of …

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