A Holistic View of Lexical Choice
Deutsches Fortschungszentrum fur Kunstliche Intelligenz
D-6600 Saarbrucken 11
Recently the problem of choosing communicatively adequate lexemes has attracted much interest in the NL generation community. The problem is so fascinating because it includes a variety of subproblems that relate to all parts of the generation process. Up to now, many of the subproblems have been identified, and solutions have been suggested for each. However, steps towards an integrating approach to lexical choice are still missing.
Whether lexical choice must be exact in the sense that all and only the intended meaning is conveyed, depends on the respective communication situation. In a multimodal discourse, where language is supplemented by gestures or graphics, the linguistic device need not convey everything to the partner. In written discourse without shared contextual knowledge, exact verbalization seems much more in order. We will concentrate here on communication with NL as the only mode.
Lexical choice as a knowledge-based process
Lexical choice" has become a general term for a variety of subproblems that involve the mapping from conceptual entities to lexical ones:
Definite reference: If a set of discourse referents is selected for verbalization, they must be described by concepts and, eventually, words that allow for an unambiguous identification of the referents. This includes the appropriate use of proforms.
Choice of open class words: Given a conceptual representation of the intended literal meaning, lexemes must be selected from a set of candidate lexemes that are communicatively appropriate in the given situation.
?This research was supported by the German Federal Minister for Research and Technology under grant no. ITW 9002.