The keynote article in this issue describes some empirically demonstrated beneficial functions of radio in development communications: (1) it improves the quality and relevance of education; (2) it keeps educational costs down; (3) it broadens access to education; and (4) it extends the impact of time, money, and effort outside the formal education system through such applications as open radio broadcasting, radio campaigns, and radio-listening groups. Other articles are concerned with the new U.N. Audio-Visual Information Center on Human Settlements, called Vision Habitat; defining broadcasting training needs; the use of radio in classroom instruction; two-way radio for health and development; successful scriptwriting; communication planning; the training and visitation system of agricultural extension; and a discussion about development project failures. Case studies deal with medicine and CB radios in Guyana, teacher training with radio in Nepal, and a satellite demonstration in the West Indies. (CMV)