According to Wickens (1992) the role of Engineering Psychology is distinct from both Psychology and Engineering in that it arises from the intersection of the two domains. He also distinguishes Engineering Psychology from Ergonomics (see note 1) to suggest that “the aim of engineering psychology is not simply to compare two possible designs for a piece of equipment .. but to specify the capacities and limitations of the human … from which the choice for a better design should be directly deductible” (pp. 3-4, Wickens, 1992 cites Poulton, 1966).
Engineering psychologists are concerned first with the distribution of system functions among people and machines. System functions are identified through the analysis of system operations. Engineering psychologists typically work backward from the goal or desired output of the system to determine the conditions that must be satisfied if the goal is to be achieved. Next, they predict – on the basis of relevant, validated theory or actual experimentation with simulated systems — whether the functions associated with each subgoal can be satisfied more reliably and economically with automation or human participation.
Usually it turns out that the functions assigned to people are best performed with machine assistance in the form of sensing, processing, and displaying information and reducing the order of control. Not only should automation unburden operators of routine calculation and intimate control, but also it should protect them against rash decisions and blunders. The disturbing notion that machines should monitor people, rather than the converse, is based on the common observation that people are poor watchkeepers and, in addition, tend to be forgetful. This once radical notion is now a cornerstone of modern system design