SOME HIGHLY DEVELOPED TEACHING DEMONSTRATIONS WERE TESTED TO DETERMINE THEIR EFFECTIVENESS IN PRODUCING A SPECIFIC VARIETY OF BEHAVIOR CHANGES IN INSERVICE ELEMENTARY SCHOOL TEACHERS AND IN STUDENTS PREPARING TO TEACH. THE INVESTIGATOR FOCUSED UPON DETERMINING THE VALUE OF THE FORMAL TEACHING DEMONSTRATION FOR PROMOTING TEACHER DEVELOPMENT. THE EXPERIMENTAL DESIGN INVOLVED THREE GROUPS OF SECOND- AND THIRD-GRADE TEACHERS IN AN INSERVICE EDUCATION PROGRAM, PLUS A SIMILAR NUMBER OF COLLEGE STUDENTS IN ELEMENTARY TEACHER PREPARATION. THE THREE GROUPS WERE EXPOSED TO A SERIES OF TEACHING DEMONSTRATIONS IN A UNIFORM FASHION. DATA GATHERING INVOLVED A SELF-REPORT INVENTORY PLUS A SERIES OF CLASSROOM OBSERVATIONS BY TRAINED INDEPENDENT OBSERVER-ANALYSTS. EFFECTED CHANGES MEASURED BY PRE- AND POST-TEST DIFFERENCES WERE SIGNIFICANTLY LARGE. IT WAS CONCLUDED THAT FORMAL DEMONSTRATIONS DO PROMOTE CHANGES IN TEACHER AND STUDENT BEHAVIOR OF SPECIFIC KINDS AT A SIGNIFICANT LEVEL. (GD)