TWO HIGH SCHOOL PHYSICS CLASSES WERE CHOSEN TO BE EXPERIMENTAL GROUPS IN A STUDY OF THE EFFECTIVENESS OF AUDIOVISUAL MEDIA USED IN A COMPLEMENTARY (RATHER THAN SUPPLEMENTARY) ROLE IN THE INSTRUCTIONAL PROCESS. FOUR CLASSES TAUGHT BY TWO TEACHERS COMPRISED THE CONTROL GROUP. THE EXPERIMENTAL DESIGN WAS COMPLICATED IN THAT THE GROUPS WERE STRATIFIED ALONG FOUR DIMENSIONS, NAMELY, COMPLEMENTARY ROLE OF AUDIOVISUAL MEDIA, TEACHER COLLABORATION, VARIABLE CLASS STRUCTURE, AND FREE ACCESS TO THE SCHOOLS' RESOURCES. THE INSTRUCTIONAL MATERIALS CONSISTED OF THE ORGANIZED COLLECTION OF ACTIVITIES DESIGNED BY THE PHYSICAL SCIENCE STUDY COMMITTEE. MORE CHANGES WERE OBSERVED IN THE TEACHERS THAN IN THE STUDENTS IN THIS EXPERIMENT. (JK)