THE EFFECTS OF VARIATIONS IN EXTERNALLY DIRECTED TEMPO (OPPOSITE OF SELF-PACING) ON PROGRAMED LEARNING PERFORMANCE WERE INVESTIGATED. THIS REPRESENTED THE SECOND IN A SERIES OF THREE STUDIES CONCERNING THE RELATIONSHIP BETWEEN PACING MODE AND BEHAVIOR. (REFER TO ACCESSION NUMBERS ED 003 199, ED 003 201, AND ED 003 202 FOR ADDITIONAL INFORMATION ON THIS PROJECT.) THE 277 SUBJECTS WERE EIGHTH-GRADERS DRAWN FROM 8 SEPARATE CLASSES. LESSON MATERIALS CONSISTED OF SELF-PACED PHYSICS PROGRAMS ADMINISTERED IN SCHOOLS PRIOR TO THIS EXPERIMENT ON FIXED PACING. PROGRAMED MATERIALS (PHYSICS) WERE PRESENTED AT A FIXED PACE DURING THE MAIN EXPERIMENT AT A TELEVISION STUDIO. FINDINGS WERE--(1) INCREASES IN TEMPO PRODUCED PERFORMANCE DECREMENTS, (2) UNDER FIXED TEMPO CONDITIONS, STUDENTS VARYING IN ABILITY AND WORK RATE WERE IMPAIRED, AND (3) GROUP PERFORMANCE UNDER SLOW, FIXED TEMPOS WAS SUPERIOR TO GROUP PERFORMANCE UNDER SELF-PACED CONDITIONS. THESE RESULTS WERE DISCUSSED IN TERMS OF RECOMMENDATIONS FOR SITUATIONS IN WHICH SELF-PACING OR FIXED PACING CAN MORE APPROPRIATELY BE USED. (JC)