It has been suggested that in science education the immediacy and pervasiveness of television and its ability to bring the world into the classroom could be effectively used by the teacher. The motivational uses of instructional television in a high school environmental science class were studied with 57 tenth graders at a suburban high school. Units on soil and energy resources were used alternatively as control and experimental groups, with only live teacher instruction in the control condition and with televised instruction as a supplement to teacher instruction in the experimental condition. A motivation instrument used a semantic differential to measure student beliefs. Results suggest that the televised instruction did not produce significant differences in the learner's understanding, perceived value of the units, achievement test scores, or motivation. The impact of television might have been more apparent if student discussion had followed the presentations or if teacher guidance had been applied to aspects of the lessons. Eight tables present study data. (Contains 43 references.) (SLD)