The use of natural language processing in computer-assisted language instruction

This article describes the natural language processing techniques used in two computer-assisted language instruction programs: VERBCON and PARSER. VERBCON is a template-type program which teaches students how to use English verb forms in written texts. In the exercises verbs have been put into the infinitive, and students are required to supply appropriate verb forms. PARSER is intended to help students learn English sentence structure. Using a lexicon and production rules, it generates sentences and asks students to identify their grammatical parts. The article contends that only by incorporating natural language processing techniques can these programs offer a substantial number of exercises and at the same time provide students with informative feedback. Alan Bailin is director of the Effective Writing Program at the University of Western Ontario, London, Ontario, Canada. Philip Thomson is a programmer in the Faculty of Medecine, University of Western Ontario.