A study was conducted utilizing new adult Interstate Distributive Education Curriculum Consortium (IDECC) curriculum materials to evaluate through experimental research the effectiveness of IDECC's systematic teaching approach. The study was quasi-experimental involving two levels of treatment: (1) the adult IDECC teaching approach and (2) the postsecondary traditional teaching approach. Sixteen classes were randomly selected from a population of thirty volunteer sites. The IDECC approach utilized selected adult IDECC competency-based materials as their unit of instruction. The traditional instructors developed lesson plans as their instructional material within a workshop setting. Findings based on analysis of covariance by regression utilizing forty-eight sources of variance indicated that five sources of variance made a significant contribution: school, student educational level by student education level, student occupational experience by student occupational experience, teaching approach by student past participation in distributive education programs, and student age by student occupational experience. (Appended material includes a unit of instruction outline, objectives and resources utilized in the study, pretest and posttest questionnaires, and the IDECC instructor's material.) (LRA)