AN ANALYSIS OF A FIELD TEST OF SCIENCE LEARNING MATERIALS FOR ABLE ELEMENTARY STUDENTS IS REPORTED. THE LEARNING MATERIALS FIELD TESTED AND EVALUATED WERE UNGRADED INDEPENDENT STUDY KITS. THEY WERE DESIGNED FOR MAXIMUM SUITABILITY REGARDLESS OF TEACHER OR SCHOOL CIRCUMSTANCES. THE LEARNING MATERIALS INVOLVED CONCEPT FORMATION IN THE TOPICS OF ATOMS, MOLECULES, AND MEASUREMENT. TWO HUNDRED FIFTY-NINE STUDENTS FROM 31 DIFFERENT ILLINOIS SCHOOLS USED THE MATERIALS. STUDENTS IN THE STUDY WERE SELECTED BY THEIR TEACHERS AND ADMINISTRATORS. METHODS OF USING THE MATERIALS WERE ESTABLISHED BY THE TEACHERS. PRE-TESTS AND POST-TESTS WERE ADMINISTERED TO THE STUDENTS. RESULTS ARE REPORTED FOR EACH TEST ITEM AND EACH GRADE LEVEL. THE AUTHORS CONCLUDED THE LEARNING MATERIALS TESTED CAN BE USED EFFECTIVELY. GREATER SUCCESS IN USE IS PREDICTED FOR GRADES 2 AND 3 THAN FOR GRADES 1 AND 4. (RS)