A structured approach to designing human-computer dialogues

Abstract

This article presents a conceptual model and software tool for designing and implementing flexible human-computer dialogues. The tool is referred to as a dialogue generator. The rationale for building such a tool is discussed in the context of other work in the literature, and is based on a fully operational version written in APL. A dialogue generator is important because of the cost of designing dialogues, and the rapidly increasing importance of dialogue generation due to the proliferation of interactive applications of computers. A command language model is used for the target dialogue because of its inherent simplicity, which promotes a structured and streamlined approach based on interaction events, which are described in tabular form in the dialogue data-base. “Help” and “abort” facilities are provided, as are facilities for controlling the flow of the dialogue. The implementation is discussed, particularly in terms of how to represent the various types of information pertaining to an interaction event, and how to store and organize the information. The concepts of user guided and system guided dialogues are re-examined in the context of the flow-control mechanism. Both styles of dialogue are needed, depending on the user, and both can be covered by the model described. The model is compared with others in the literature, and its capabilities are evaluated against published rules for dialogue programming.