INTEGRATING USER AND COMPUTER-SYSTEM CONCERNS IN THE DESIGN OF INTERACTIVE SYSTEMS

In any design process, there are different perspectives that need to b e accommodated. For the design of interactive systems, two of these ar e that of the computer system designer and that of the end user. The f ocus of this paper is on tools or notations to support the integration of these different perspectives-in particular, system modelling and t heory-based user modelling. There are few established techniques for d oing such integration; those that there are generally involve a loose coupling between the description of the system and that of the user, o r are skewed towards one or other of these viewpoints. Recently, techn iques that deal with the system and user more symmetrically have emerg ed. We focus, in particular, on techniques that have been developed an d investigated within a large European project, Amodeus. These allow t he analyst to explore properties of the conjoint system, and to invest igate how the properties of the interaction relate to those of the ind ividual agents. However, there is a trade-off, which can be characteri zed as increased power to critique a design being offset against reduc ed generality in the design perspectives that can be considered using the technique. We argue that while such techniques require a high init ial investment, technological advances make the need for such integrat ed approaches urgent. We consider what resources each class of techniq ue demands and what kinds of results each yields. (C) 1997 Academic Pr ess Limited.