Formal descriptions of user interfaces

The purpose of HCI research should be to produce predictive theories of user and system behaviour which are culled from experience with existing interactive systems and can be applied to the design and evaluation of future ones. The author outlines a formal approach to interactive system design, motivated by a desire to show how theories from the user´s perspective can be associated to theories of design. Demonstration of the link between concepts in software engineering and HCI, such as that given for refinement and the model-world metaphor should convince researchers with different perspectives to concentrate more closely on how to make their separate theories compatible