ABSTRACT
This section covers two systems that bridge the text-based tutors of Section I and the graphics-based tutors of Section III. These are the dialogue-based language teaching games---Sanders and Sanders' spy game, Spion, and DeSmedt's detective game, Herr Kommissar. The pedagogical goal is to give students conversation-like practice in the target language. The medium is textual, as in Section I; there is no significant pictorial component. Each system uses the convention of the mystery scenario to constrain the dialogue, following the model of commercial electronic adventure games. The scenario, with its ration of objects and actions, limits the language expected of students and simplifies the job of the natural language processor.26
