"This work studies the problems of audio-visual education, chiefly those concerning the teacher and his contact with his pupils — Understanding, a barrier to communication — Tasks of instruction and reception by the pupils — Next it examines the various materials which the teacher can use for communication: the blackboard, pictures and photos, posters, cartoons and comics, graphs, maps and globes, 3-dimensional media, sound equipment, films, television and the teaching machine; a section is devoted to each of these media." (Jean-Marie Van Bol, Abdelfattah Fakhfakh: The use of mass media in the developing countries. Brussels: CIDESA, 1971 Nr. 2485, topic code 510)