THIS STUDY INVOLVED 74 EIGHTH-GRADE STUDENTS AND THEIR YEAR-LONG WORK ON A PROGRAMED COURSE IN GENERAL SCIENCE. THE SUBJECTS WERE DIVIDED INTO FOUR TREATMENT GROUPS VARIED AS TO IN- OR OUT-OF-CLASS USE OF THE PROGRAM. TWO MEASURES WERE TAKEN--AN ACHIEVEMENT MEASURE OVER THE SUBJECT-MATTER CONTENT OF THE PROGRAMED COURSE, AND A PERFORMANCE MEASURE (NUMBER OF CORRECT FRAME-TO-FRAME RESPONSES). THESE MEASURES WERE RELATED TO METHOD OF PROGRAM USE (TREATMENT) AND INDIVIDUAL LEARNER CHARACTERISTICS. THE FINDINGS OF THIS STUDY HAVE IMPLICATIONS FOR SCHOOL PRACTICE RELATIVE TO THE UTILIZATION OF PROGRAMED INSTRUCTION AND LEARNING PRINCIPLES AS THEY HAVE BEEN APPLIED TO THE CHARACTERISTICS OF PROGRAMED INSTRUCTION. (LP)