Two studies examine the nature of Japanese elementary school and junior high school students' preconceptions about media, the effects of teachers on these preconceptions, and the effect of such preconceptions on learning from instruction in multimedia situations. In the first study, 109 fifth graders reported their preconceptions toward watching television, using a computer, reading, writing, and listening to a teacher in aspects of preference, difficulty, and learning expectancy. Preconceptions about media activities were related to teachers' patterns of media use in classes, and preconceptions were also connected with learning from these instructions. In the second study, 134 eighth graders were asked the same preconception questions, with additional questions on their perceptions of the realism of media and their causal attributions of success and failure in learning from media. These results support those of the first study in suggesting that there is a reciprocal interaction among learners' preconceptions about media, teachers' media utilization, and performance in learning from media. Nine tables and three figures illustrate the discussion. Eight transparencies have been reproduced and included. (SLD)