In applying the Professional Performance Situation Model to the medical technology profession, situations describing actual laboratory performance are used as a basis for defining competence. As these definitions of competence are derived, appropriate criterion-referenced (domain-referenced) assessments are designed to measure the achievement of competence. This paper describes the process by which situations representing clinical practice are derived, the extrapolation of skill and knowledge statements reflecting expected performance, the generation of domains of competence, the design of criterion-referenced assessments, and some examples of prototype instruments used to assess attainment of the competence. The techniques include multiple choice items, checklists for use in the clinical component of the educational experience, and the adaptation of the written simulation for instruction and evaluation in medical laboratory sciences education. Validity of this approach is discussed, as well as possible implications for its use in developing assessments to measure continued competence in the profession beyond the baccalaureate education.