A study was commissioned by a large petrochemical concern in order to validate professional degrees as a job entry requirement. The investigations considered two issues: (1) "Are activities performed by professionals (chemists and engineers) measurably different from the activities of subordinate technical personnel?" and "What aspects of professional education lead to professional competence?" Divided into two parts, the study initially employed the position analysis questionnaire (a standardized worker-oriented job element analysis instrument) in contrasted group comparisons of 420 professionals and 215 non-professionals. In the second study, restricted to 420 professionals, the critical incidents technique for analyzing job duties was utilized. In a cross validation technique, performance incidents elicited from individual chemists were independently reanalyzed by other chemists. Results of the various analytic techniques indicated that the curricula of professional education programs in chemistry and engineering can be related in a measurable way to professional competencies. (Author/CSS)