Focusing on assessment centers, this chapter is one of seven in a report that examines the assessment of occupational competence. Assessment centers are presented first in a historical context (their origins in personality theory), through which their evolution is traced and examined. What follows is a description of current assessment center practice, involving a broad sample of presently active assessment centers. The third major portion discusses the process and the results of the assessment center to illuminate the following key issues for the researcher and practitioner: Is the assessment center useful as a method of ascertaining the presence or absence of specified competencies? Does it measure performance potential or current ability? To what use do organizations put the data that they gather on individuals? What are the consequences of implementing assessment centers for the persons who are assessed and for the implementing organizations? The chapter concludes with an examination of the functions assessment centers serve for the organizations that use them. (Other sections of the report are available separately--see note. The first is an overview; the last is a synthesis of issues.) (LRA)