Comparing non-deterministic models of tasks and de- vices
Panos Markopoulos · 2000
. This paper discusses a simple model of the temporal behaviour of users and devices. A range of possible comparisons that can be drawn between the two models is examined. Without assuming a theory of cognition or a process model for user interface software design, this exercise reveals a significant range design issues and demonstrates how the simplest models of interaction can provide a framework for reasoning about usability. Keywords. Labelled Transition Systems, Observational Equivalence, Testing, Task Conformance, Design of Interactive Systems. 1. Introduction This paper discusses the semantics underlying the comparison between models of user behaviour to models of interactive systems. The formal framework for this discussion is that of Labelled Transition Systems (LTS). This is a very simple and general model of behaviour which underlies many languages for the specification of concurrent systems, that have also been used for the specification of interactive systems. Hig...