Mental models-panacea or sidetrack?

Within the world of human factors-whether applied to human-computer interaction or to man-machine systems-fundamental questions must be answered about mental models. It is necessary to propose what a mental model is, how it is identified and represented, and how it is applied in systems analysis and design. The authors argue that there is room for two notions of mental model, the first and weaker one being a necessary stepping-stone to identifying the second, but also have utility itself. In this view, a user´s conceptual model would refer to that internal representation, regarded almost as axiomatic by some in human factors, that constitutes people´s topographical, structural and functional system understanding. By `running´ such a kind of system simulation they can describe, explain or predict system behaviour; the model is often hypothesised as being accompanied by, or even embodied in, visual imagery. The article discusses these principles and the identification of mental models