Situation Awareness and Workload: Birds of a Feather?

1. SUMMARY from a set of desired states or goals, the dynamics of the controlled system and the interactions between system variables. This knowledge forms an internal representation or mental model of the process to be controlled. The concept of a mental model, which the operator develops and draws upon when making operational decisions, is central to the idea of situation awareness, and has become an aspect of particular concern to engineers and behavioural scientists involved in the development of complex human-machine systems. In this paper it is argued that an hierarc ical information processing model, with a basi in perceptual control theory, provides the necessary framework for interpreting a large, unfocused empiric