tailieunhanh - Báo cáo khoa học: "Lexical Selection in the Process of Language Generation"

In this paper we argue that lexicalselection plays a more important role in the generation process than has commonly been assumed. To stress the importance of lexicalsemantic input to generation, we explore the distinction and treatment of generating open and closed cla~s lexical items, and suggest an additional classification of the latter into discourse-oriented and proposition-oriented items. Finally, we discuss how lexical selection is influenced by thematic ([oc~) information in the input. . | Lexical Selection ỉn the Process of Language Generation James Pustejovsky Department of Computer Science Brandeis University Waltham MA 02254 617-736-2709 Abstract In this paper we argue that lexical selection plays a more important role in the generation process than has commonly been assumed. To stress the importance of lexical-semantic input to generation we explore the distinction and treatment of generating open and closed class lexical items and suggest an additional classification of the latter into discourse-oriented and proposition-oriented items. Finally we discuss how lexical selection is influenced by thematic focus information in the input. 1. Introduction There is a consensus among computational linguists that a comprehensive analyzer for natural language must have the capability for robust lexical disambiguation . its central task is to select appropriate meanings of lexical items in the input and come up with a non contradictory unambiguous representation of both the propositional and the non-propositional meaning of the input text. The task of a natural language generator is in some sense the opposite task of rendering an unambiguous meaning in a natural language. The main task here is to to perform principled selection of a lexical items and b the syntactic structure for input constituents based on lexical semantic pragmatic and discourse clues available in the input. In this paper we will discuss the problem of lexical selection. The problem of selecting lexical items in the process of natural language generation has not received as much attention as the problems associated with expressing explicit grammatical knowledge and control. In most of the generation systems lexical selection could not be a primary concern due to the overwhelming complexity of the generation problem itself. Thus MUMBLE concentrates on grammar-intensive control decisions McDonald and Pustejovsky 1985a and some stylistic considerations .