This review of the technical possibilities of audio, television, computing, and combination media addresses the main factors influencing decisions about each technology's suitability for distance teaching, including access, costs, symbolic representation, student control, teacher control, existing structures, learning skills to be developed, and feedback. Specific technologies are considered by type as follows: (1) audio: radio, audiocassettes, telephone teaching; (2) television-based: broadcast, cable, and satellite television, videocassettes, and videodiscs; (3) computer-based: hardware developments and some of the functions of microcomputers, computer assisted learning (CAL), computer conferencing, and audiographics systems; and (4) combination systems: computer and videodisc technologies and viewdata, which combines telephone, computer, and television technologies. Questions are raised concerning the potential social and educational effects of introducing these newer technologies to distance education; their cost-effectiveness; their potential impact on the nature of distance education; and whether they should be used in poorer developing countries. Four references are listed. (LMM)