This report presents the results of an extensive mail survey of Ontario elementary and secondary school teachers which was conducted in 1990 to explore their use of school television and video, and of TVOntario instructional programs and support materials. Where possible, the findings have been compared with those of a similar survey conducted in 1985. Based on responses received from 1,661 teachers (a 50.3% return), the report provides detailed information on the use of television and video in the classroom, the use of selected TVOntario broadcast programs and series, teacher attitudes toward educational television usage, school system support for television and video use, and the use of television for professional development. Teachers reported that secondary science programming and the School Broadcasts publication and TVOntario teachers' guides have been the most successful; fewer teachers have used other TVOntario publications or obtained assistance from TVOntario-trained television resource teachers. Teachers' responses also indicate that they have adopted video and educational television as a valuable aid, and that they are using varied approaches to integrating video use in instruction. The narrative report is supplemented by 21 tables, and a summary in French is provided. (DB)