AS A BEGINNING FOR THIS STUDY, CONDUCTED AT THE UNIVERSITY OF WISCONSIN-EXTENSION, A THREE-SUBJECT CURRICULUM WAS DEVELOPED FOR AN AREA OF LAW ENFORCEMENT THAT HAD PROVEN PARTICULARLY DIFFICULT FOR STUDENTS TO LEARN, CRIMINAL LAW. FOR EACH OF THE THREE SUBJECTS, SETS OF MATERIALS WERE PREPARED INCLUDING AN INSTRUCTOR'S GUIDE, FILMS, AND A PROGRAMMED INSTRUCTION MANUAL FOR STUDENTS. MATERIALS AND METHODS WERE EVALUATED; ONE OF THE THREE TOPICS WITHIN THE CURRICULUM WAS CHOSEN AT RANDOM. THIS SUBJECT WAS TAUGHT TO FOUR GROUPS OF LAW ENFORCEMENT STUDENTS USING FOUR COMBINATIONS OF TECHNIQUES AND MATERIALS. IN THE FIRST APPROACH, THE INSTRUCTOR TAUGHT THE CONTENT OF THE COURSE THROUGH LECTURES; IN THE SECOND, THE INSTRUCTOR LECTURED, USING BOTH THE INSTRUCTOR'S GUIDE AND FILMS. IN THE THIRD APPROACH, THE INSTRUCTOR LECTURED, USED THE INSTRUCTOR'S GUIDE AND FILMS, AND STUDENTS USED THE PROGRAMMED-INSTRUCTION MANUALS. THE FINAL APPROACH CONSISTED OF AN INDEPENDENT STUDY GROUP USING FILMS AND THE MANUAL; THERE WAS NO INSTRUCTOR. TO DETERMINE THE EFFECTS OF THESE DIFFERENT APPROACHES, THE STUDENTS WERE TESTED BEFORE AND AFTER COURSE COMPLETION. TEST RESULTS SHOWED THAT THE GREATEST GAIN IN KNOWLEDGE WAS MADE BY STUDENTS IN THE INDEPENDENT STUDY CLASS (APPROACH FOUR), FOLLOWED BY STUDENTS IN GROUP THREE. THE FIRST APPROACH WAS THE LEAST SUCCESSFUL. ALTHOUGH THE FINDINGS OF THE STUDY ARE STRONG AND CONCLUSIVE, IT IS SUGGESTED THAT COMPARATIVE WORK INVOLVING A LARGER NUMBER OF STUDENTS THAN THE 42 PARTICIPANTS INVOLVED HERE IS NECESSARY BEFORE THE DATA CAN BE CONSIDERED BROADLY APPLICABLE. TABULAR DATA AND FOOTNOTE REFERENCES ARE INCLUDED IN THE STUDY. (LWM)