STUDENTS WERE PRESENTED 61 LESSONS BY MEANS OF SEMIAUTOMATIC TEACHING MACHINES. LESSONS WERE ARRANGED SO THAT EACH PARTICIPATING STUDENT STUDIED PART OF THE COURSE MATERIAL WITH A SINGLE REPETITION AND PART WITHOUT REPETITION. DATA WERE OBTAINED FROM TWO TESTS SHOWING TEACHING-MACHINE RESULTS AND ONE FINAL COURSE EXAMINATION. NO SIGNIFICANT DIFFERENCES OCCURRED AS A RESULT OF THE LESSONS BEING REPEATED. STUDENTS REPORTED THAT THEY COULD MEMORIZE ANSWERS WHEN THEY TOOK THE LESSONS THE FIRST TIME, AND THAT REPETITION DID NOT CONSTITUTE AS MUCH OF A REVIEW AS IT MIGHT HAVE HAD THE MATERIAL BEEN DIFFERENT. (JH)