Using 280 5th graders as subjects, an experiment was carried out to answer the following questions: (1) do certain indentified television formats have effects on cognition? (2) Is mastery of various cognitive skills correlated with extraction of knowledge from a television message which employs the corresponding format? It was hypothesized that: (1) if a television message is heavily loaded by a particular format, then extraction of knowledge from the message depends on one's initial mastery of the cognitive skill which is hypothesized to be needed; (2) if the same message is coded in a different way, mastery of another mental skill correlates with the extraction of knowledge; and (3) when the message supplants the skill, no such correlation with the corresponding skill occurs. The experiment supported the first hypothesis and, in part, the second. The third hypothesis received strong support. In addition, the experiment demonstrated that the television formats identified were critical to cognition, different formats tapped different cognitive skills, and various television formats were expected to have cognitive developmental effects. (HAB)