The Key Assessment System, consisting of test instruments which measure psychological functioning, work related competencies, and attitudinal and motivational characteristics, is described. The system is a vocational assessment battery designed to differentiate levels of psychophysical capabilities in a nondiscriminatory manner. It provides a mechanism for identifying vocational capabilities and making optimal vocational recommendations. The Key Tabletop Lab and the Key Audiometer are designed to minimize the threatening aspects of testing. Computer technology is utilized to produce and maintain norms specific to the sample being tested. When large groups of individuals from distinct populations are tested, it will be possible to develop unique norms for each group. Separate evaluative criteria will be available for distinct populations. Theory suggests that the more specific the criteria, the more precise the recommendation. To make the system useful in the prediction of performance in practical areas, a core set of physiological functions was established to identify performance capabilities based upon human attributes. (DWH)