Dialogue control functions and interaction design

This paper is concerned with the design of interactive teaching systems from the point of view of dialogue theory. It is argued that transparency and naturalness are important qualities of a dialogue for the student, helping him to concentrate on the learning task (thanks to naturalness) and to understand his own performance (thanks to transparency). It is argued that these qualities are also important for system design, since they result in student communicative behaviour that is easier to understand. A concise, non-technical description is provided of the framework of Dynamic Interpretation Theory, an approach to dialogue developed especially for information dialogues. On this approach, a dialogue is viewed as a sequence of complex elements of communicative behaviour, intended to change the dialogue context. The elements of communicative behaviour are analysed as simultaneously expressing a variety of`dialogue acts'; dialogue acts being deened as the functional units used by the speaker to change the context. Based on a fairly detailed analysis of the notion of context which is relevant here, a system of communicative functions of dialogue acts is developed with a focus on`dialogue control' functions, i.e., functions speciic to the management of the interaction. It is argued, and illustrated with some examples, that the understanding and application of the notions of transparency and naturalness can beneet from using the concepts of Dynamic Interpretation Theory, and that these concepts are also of importance for the construction and maintenance of adequate student models by the system.