Coupling structural and functional models for interaction design

Model-based interaction design is a promising approach to the problem of building sophisticated interactive systems. Although many models and model-based design methods have been proposed, in practice their effectiveness has tended to be limited to solving fragmented design problems. One factor that has diminished the effectiveness of previous approaches has been their inability to integrate the various models used for different aspects of the overall design problem. This paper proposes a novel approach for combining a structural model and a functional model for complicated interaction design. Formal correspondence between the models is defined and a conversion process to transform from one model to the other and vice versa is introduced. The functional model, OCD, is an efficient technique for representing task procedures, while the structural model, statechart, is well suited to representing system behavior. The usability needs and system requirements are introduced into the design process through either representation. Then, the constraints formed by a decision in a model can be seen by the designer in the other model through transformation. The possibility of automatic conversion between the models warrants the consistence between the models through the design process even when the models should continually evolve