THIS STUDY PROVIDES A PORTFOLIO OF SEVERAL THOUSAND FIELD-TESTED MULTIPLE CHOICE TEST ITEMS COORDINATED WITH THE CHAPTERS OF THE BIOLOGICAL SCIENCES CURRICULUM STUDY (BSCS) YELLOW VERSION TEXTBOOK. THE ITEMS WERE DEVELOPED BY A TEAM OF HIGH SCHOOL BIOLOGY TEACHERS AND WERE EVALUATED UNDER CLASSROOM CONDITIONS WITH GRADE 10 STUDENTS. A POINT-BISERIAL COMPUTER-BASED PROGRAM WAS DEVELOPED AND USED TO PROVIDE EVALUATION INFORMATION ON THE TEST ITEMS. IDENTIFIED FOR EACH ITEM ARE (1) BSCS THEME WITH WHICH IT DEALS, (2) THE ABILITY CATEGORY WHICH IT IS MEASURING, (3) THE LEVEL OF DIFFICULTY, (4) ITS DISCRIMINATION BASED ON AN INTERNAL CRITERION--TOTAL TEST SCORES, AND (5) ITS DISCRIMINATION BASED ON AN EXTERNAL CRITERION--THE VERBAL REASONING SECTION OF THE DIFFERENTIAL APTITUDE TEST. THE PROTOCOL DESCRIBED FOR DEVELOPING TEST ITEMS, FOR FIELD TESTING THESE ITEMS, AND FOR EVALUATING THEM COULD BE ADAPTED BY OTHER TEACHING GROUPS IN DEVELOPING TEST ITEMS APPROPRIATE TO THEIR OWN TEACHING SITUATION. (DS)