THE USE OF PRACTICE TESTS AS A LEARNING AID WAS EVALUATED. ATTEMPTS WERE MADE TO DEMONSTRATE HOW DATA PROCESSING EQUIPMENT COULD BE USED EFFECTIVELY TO REPRODUCE TESTS AND ANALYZE TEST RESULTS FOR IMPROVEMENT OF INSTRUCTION. INITIALLY, A CLASS OF STUDENTS IN TESTS AND MEASUREMENTS AT NORTH DAKOTA STATE UNIVERSITY (THE REFERENCE GROUP) WAS ADMINISTERED FIVE UNIT TESTS AND FINAL EXAMINATION. THE TEACHING PROCEDURES FOLLOWED THE USUAL LECTURE-DISCUSSION METHOD. A SECOND CLASS IN TESTS AND MEASUREMENTS (THE EXPERIMENTAL GROUP) WAS TAUGHT BY A DIFFERENT METHOD BUT ADMINISTERED THE SAME UNIT TESTS AND FINAL EXAMINATION AS THE REFERENCE GROUP. LECTURES WERE COMPRESSED TO PERMIT TIME FOR A PRACTICE TEST FOLLOWED BY DISCUSSION TO PRECEDE EACH UNIT TEST. THE PRACTICE TESTS WERE PARALLEL IN CONTENT AND DIFFICULTY WITH THE UNIT TESTS. THE DATA INDICATED HIGHER MEAN SCORES FOR THE GROUP WHICH WAS ADMINISTERED THE PRACTICE TESTS. FORTY-SEVEN OUT OF 48 DIFFERENT COMPARISONS FAVORED THE EXPERIMENTAL GROUP WHEN SEPARATE CONSIDERATION WAS GIVEN TO VARIOUS UBGROUPS. A LARGE MAJORITY OF THE STUDENTS FAVORED THE USE OF PRACTICE TESTS FOLLOWED BY DISCUSSION OF RESULTS. THE DATA PROCESSING EQUIPMENT PROVIDED AN EFFECTIVE MEANS FOR REPRODUCING TEST BOOKLETS AND SERVED AS AN AID FOR PLANNING INSTRUCTION TO COVER POINTS NOT FULLY UNDERSTOOD BY THE CLASS. OVERALL, USE OF PRACTICE TESTS AND DATA PROCESSING EQUIPMENT IS BELIEVED TO HAVE CONTRIBUTED TO EFFECTIVE LEARNING IN THIS EXPERIMENTAL STUDY.