Argues that too much of the wrong kind of research has been carried out, using inappropriate methods, and proposes a framework for investigating the effectiveness of educational media. Twenty-seven references are listed. (LLS)

This study examines alternatives to direct transmission of television and radio programs for courses with low student enrollment at the Open University. Examined are cut-off points in terms of student numbers at which alternative means of distributing audio or audio-visual materials become more economical than direct television or radio…