REPORTED ARE THE ADAPTATION OF THE BIOLOGICAL SCIENCES CURRICULUM STUDY (BSCS) YELLOW VERSION BIOLOGY FOR USE IN ISRAEL AND A DESCRIPTION OF A FEEDBACK AND EVALUATION SYSTEM WHICH IS BEING USED IN COMPARING THE BSCS ADAPTATION TO THE CONVENTIONAL ISRAELIAN BIOLOGY PROGRAM. PART 1 DEALS WITH THE ADAPTATION OF THE BSCS MATERIALS WHICH WAS DONE BY 25 BIOLOGY TEACHERS FROM VARIOUS TYPES OF ISRAELIAN SECONDARY SCHOOLS (ACADEMIC, AGRICULTURE KIBBUTZIM). A TEXTBOOK, LABORATORY MANUAL FOR THE STUDENT, AND A BOOK FOR THE TEACHER WERE PREPARED SIMULTANEOUSLY. THE PRIMARY TEXTBOOK AND LABORATORY CHANGES FOR EACH YELLOW VERSION CHAPTER ARE GIVEN IN THE REPORT. PART 2 DISCUSSES THE TESTING PHASE WHICH IS DIRECTED AT TWO MAJOR OBJECTIVES. THESE ARE (1) TO PRODUCE FEEDBACK INFORMATION OF TEACHING EFFICIENCY, AS MEASURED BY STUDENT ACHIEVEMENT, ON KEY POINTS IN THE TEXT, AND (2) TO PROVIDE EVALUATION DATA IN COMPARING THE BSCS APPROACH TO CONVENTIONAL BIOLOGY INSTRUCTION. BSCS QUARTERLY ACHIEVEMENT TESTS WERE ADAPTED TO PROVIDE FEEDBACK INFORMATION. THE TESTS USED ON A PRE- AND POST-TEST BASIS FOR THE COMPARATIVE ANALYSIS WERE (1) THE TEST ON UNDERSTANDING SCIENCE (TOUS), (2) INVESTIGATOR-CONSTRUCTED ATTITUDE AND BIOLOGICAL INFORMATION TESTS, AND (3) THE "MILTA" GROUP INTELLIGENCE TEST. THE CONTROLLED EXPERIMENT WAS INITIATED DURING THE 1966-67 SCHOOL YEAR. THE RESULTS OF THE ACHIEVEMENT TESTS, INCLUDING ITEM ANALYSES, ARE BEING MADE AVAILABLE TO ALL PARTICIPATING TEACHERS. (DS)