ABSTRACT
We have postulated that design is an information processing activity centered around questions that must be answered to achieve design goals. Those questions were described earlier.
The kinds of questions for which answers are sought are different for designers and HF specialists, although they overlap, as they must, if design is to be adequate. The information that designers seek is related to questions of functionality (e.g., to produce a particular effect, what kind of component, functioning in what way, is needed?). The kinds of questions specialists ask are related to the effect of the way in which functionality is achieved (i.e., the effect of that component and its functioning on what the operator must do to perform adequately). In the case of the specialist, there are actually two major questions: Is a specific system factor/characteristic important in terms of its possible effect on the operator? What is the nature of that effect? (Of course, if the specialist is given responsibility for design of the interface, he or she will also be concerned about the functionality of that interface.)
Logically, the designer should also be concerned about the effect of equipment functioning on the operator because the operator is a major subsystem of the system being designed. However, because the engineer is concerned primarily with functionality and is not a behaviorist, he or she assigns the operator responsibility to the specialist. In worst-case situations, the designer is not even aware of the operator, and the specialist must harass the designer to ensure that personnel factors are considered.
