without discussion or questions or use of blackboard. Each 
group had half an hour of exposure to the material. Each was 
asked to fill in the same quiz afterward. It was quite a surprise 
to the experimenters when the students performed better with 
TV-channelled information and with radio than they did with 
lecture and print—and the TV group stood well  above the radio 
group. Since nothing had been done to give special stress to 
any of these four media, the experiment was repeated with 
other randomized groups. This time each medium was allowed 
full opportunity to do its stuff. For radio and TV, the material 
was dramatized with many auditory and visual features. The 
lecturer took full advantage of the blackboard and class 
discussion. The printed form was embellished with an 
imaginative use of typography and page layout to stress each 
point in the lecture. All of these media had been stepped up to 
high intensity for this repeat of the original performance.