THE USE OF CASES DRAWN FROM THE HISTORY OF SCIENCE WAS EVALUATED AS AN INSTRUCTIONAL PROCEDURE USING 108 SECONDARY SCHOOL CLASSES IN BIOLOGY, CHEMISTRY, AND PHYSICS LOCATED IN WIDELY DISTRIBUTED GEOGRAPHICAL AREAS. THE PURPOSE OF THE STUDY WAS TO DETERMINE THE EFFECTIVENESS OF THE HISTORY OF SCIENCE CASES INSTRUCTION METHOD (HOSC) IN CHANGING STUDENT UNDERSTANDING OF SCIENTISTS AND THE ROLE OF SCIENCE AS A SOCIAL INSTITUTION. THE EXPERIMENTAL DESIGN WAS AN ANALYSIS OF VARIANCE WITH COVARIANCE ADJUSTMENT. BOTH MAIN EFFECTS AND INTERACTIONS WERE UTILIZED FROM WHICH THE INVESTIGATORS CONCLUDED THAT THE HOSC INSTRUCTION METHOD IS DEFINITELY EFFECTIVE IN INCREASING STUDENT UNDERSTANDING OF SCIENCE AND SCIENTISTS AND THAT THE SO-CALLED INTANGIBLE OBJECTIVES OF SCIENCE INSTRUCTION CAN BE MEASURED. (JK)