AbstractResearch on comparative efficacy of media has been flawed, giving a false impression of equipotentiality between media. Consequently, the need for workable criteria for optimal media deployment has been underestimated. A framework is proposed to help course developers design such media selection procedures. This has two ingredients: a broad categorisation of comparative merits of different media and a finer‐grained inventory of media‐distinctive techniques and teaching functions.Five media are considered in depth: radio and TV (broadcast), audio and video (cassette, with complementary notes) and print. These are then compared briefly with computer‐based media. The analysis considers six types of media characteristics: symbol system, access, controllability, student reactivity, interactivity, adaptivity. The framework was developed collaboratively over several years, with the help of theorists and practitioners in international seminars and work