THE STUDY TESTED THE FOLLOWING HYPOTHESES--(1) IN THE PERIOD IMMEDIATELY FOLLOWING EXPOSURE TO A SUBSTANTIAL AMOUNT OF TELEVISED MATERIAL, STUDENTS EXPERIENCE A REDUCED CAPACITY FOR CONSTRUCTIVE MENTAL WORK, (2) HIGH SUSPENSE MATERIALS PRODUCE A MORE MARKED SHORT-TERM EFFECT ON MENTAL ACTIVITY THAN DO STANDARD EDUCATIONAL FILM MATERIALS, AND (3) OBSERVED CHANGES ARE CONSISTENT FROM ONE AGE GROUP TO ANOTHER. SUBJECTS FOR THE STUDY (230) WERE DRAWN FROM 8TH AND 10TH GRADES FROM FOUR CALIFORNIA COMMUNITIES. THE EFFECT OF TV MATERIAL IN REDUCING CAPACITY FOR CONSTRUCTIVE MENTAL WORK APPEARS SMALLER THAN THE AMOUNT OF VARIATION FROM TEACHER TO TEACHER IN A CONVENTIONAL SCHOOL SYSTEM. THERE SEEMS TO BE NO EVIDENCE TO SUPPORT THE IDEA OF DIFFERENCE IN SHORT-TERM EFFECT BETWEEN HIGH-SUSPENSE AND EDUCATIONAL FILM MATERIAL. (JK)