It is especially important that teachers working in classrooms in rural areas of developing countries select instructional technologies that are appropriate, pedagogically sound, innovative, cost-effective, and manageable. When selecting the instructional media that will be used in a particular classroom situation, teachers should remember that the formal classroom is a social system in and of itself. Although media can never be a substitute for good two-way communication between teacher and student, it can enhance the teaching-learning process and is particularly valuable as a tool for reaching learners who are widely dispersed over vast geographical areas. Numerous research studies have evaluated the pros and cons of radio, tape-slide presentation, peer tutoring, and media and classroom ethos. Radiovision appears especially promising as an instructional medium in developing nations. Radiovision is an instructional system in which subject matter is presented through both audio and visual channels. It is a system in which students look at visuals that are presented on the screen through slide projectors, filmstrips, charts, models, and other media, and listen to explanations via a cassette player. Compared with television, radiovision is more economical, more favorable to student viewers, more easily manipulated (in the sense that material can be more easily played back), and capable of being produced by using a combination of classroom- and commercially-developed materials. (MN)