Modeling Human-Machine Interactions Using Statecharts: One Hot and Cool Example

In this paper we discuss the use of a formal approach to the problem of describing, evaluating, and specifying human-machine interaction. The statecharts language, originally conceived by David Harel [1], is used to describe the behavior of the machine (i.e., its states and transitions), interface indications (e.g., light indicators on switches), and user interaction (selecting applications, switching modes, entering parameters, etc.). We illustrate how the statecharts language can be used to describe driver interaction with a climate control system, and show how it is possible to systematically evaluate user interaction. The paper concludes with several observations about the utility of formal language for generating sound design specification of human-machine systems.