Abstract models for HCI

This paper investigates the use of formal mathematical models in the design of interactive systems and argues for the development of generic models that describe the behaviour of a class of interactive systems. In recent years a number of authors have suggested methods for modelling interactive systems using notations and frameworks drawn from software engineering mathematics. We argue that these models tend to be either: so abstract as to limit their ability to express important interaction concerns for specific systems, and limited in the degree to which they support the construction of software that conforms to the designer 's intention; or so specific to an individual system that they provide only limited re-use across development projects and are therefore likely to be too expensive to develop except in a few special applications such as safety-critical systems. We argue that it is possible to construct a generic model of a class of interactive systems at an intermediate level of abstraction. Such a model would offer wider reusability than detailed specifications of a single system, but greater expressiveness and support for software development than fully general abstract models. To support our argument we review a number of existing models in the literature and present a generic model of interactive case memories, a class of systems used in case-based reasoning.