In order to investigate the factors that affect the ability of children to decode and elaborate television information, a study was conducted in which verbal ability, spatial ability, and amount of home television viewing were examined, along with viewer attention and three levels of instruction, for their direct and interactive effects on comprehension of narrative, pictorial, and characterological television content. Aptitude-treatment interaction (ATI) effects were analyzed to determine if instruction can attenuate ability effects. Subjects for the study were fourth and fifth grade students from the regular educational programs in a school near Madison, Wisconsin. Students were randomly assigned to one of six classes--two each for the pictorial, characterization, and control instructional treatments. Aptitude tests were administered to students the week before the instructional treatments. Students' comprehension of a 1/2-hour videotape presentation was tested following completion of the instruction programs. Statistical analysis of the test results revealed that verbal ability accounted for more variance in comprehension than did spatial ability, while home viewing had no effect. No significant effects for instructional treatments were found, but ability-achievement relationships were stronger in the control groups than in the instructional groups. A reference list, six tables, and two figures are included. (Author/JL)