A guide to the field of educational technology in Britain is presented with reference to the increasing use of media in education due to the "explosions" of information and population. Descriptions of the major developments in educational technology at the present time (1968) include the use of television (both broadcast and closed circuit), programed instruction, computer-assisted instruction, and developments in the teaching of reading, languages, and mathematics. A number of more general areas are also discussed, such as the problems involved in using these new techniques in the classroom. Summaries and further reading lists appear at the end of each chapter, and a glossary and 169-item bibliography are appended. (Author/SP)