Natural Language Generation

Abstract : Generation is the process of deliberately constructing a natural language text in order to meet specified communicative goals. The goals come from another program, perhaps an expert reasoning system or a ICAI tutor, that is motivated to talk to a human user. The texts that are produced may range from a single phrase given in answer to a question, through multi-sentence remarks and questions within a dialog, to full-page explanations. This article describes AI research on natural language generation with a historical perspective, emphasizing the special character of the problems to be solved. It begins by contrasting generation with language understanding, establishing basic concepts about the breakdown of the process into components and the flow of information and decisions through it. A section of excerpts from the output of illustrative generation systems follows, showing what kinds of performance are possible and where the difficulties are. In the remainder of the article the common approaches to generation are surveyed, including characteristic messages and the nature of a generator's lexicon.