Determination of employment potential will become increasingly important in the foreseeable future, largely due to pending Federal legislation which relates to welfare reform. The heretofore "permanently and totally disabled versus able-bodied" principle in welfare reforms is being abbandoned. Pending legislative proposals dealing with welfare reform provide for considering physically impaired persons as partially disabled and partially employable simultaneously. Thus, the need to systematically and effectively assess physically impaired citizens' capacities to participate in the job market will increase. Unquestionably, rehabilitation medicine in general, and the emerging art and science of vocational evaluation in particular, will contribute much to supplying these services. While it is widely acknowledged that the vocational potential of physically impaired persons should be evaluated in an organized manner, there are differences of opinion among professional evaluators as to which approach, or approaches, are the most meritorious; The four principal approaches are: (1) mental testing, (2) work sampling, (3) situational analysis, and (4) job tryouts. Each of these approaches is explained, contrasted, and evaluated in this paper.