"How effective is television as an educational medium and how useful are researches carried out to date in this field? — The answers to these two questions are to a large extent conditioned by the nature of the audience and of the variables, such as the orientation and the structure of a nation's general educational plan — In Britain, where educational radio has constantly been progressing, the need for such studies grows all the greater — Thus Dr. Trenaman's survey is of considerable importance, although it deals only with adults — The experiments carried out by the author determine the factors in televiewers which determine whether a programme is effective: understanding, knowledge, interests and attitude, as well as the factors in the programme itself (in this case TV programmes) which contribute to a positive message." (Jean-Marie Van Bol, Abdelfattah Fakhfakh: The use of mass media in the developing countries. Brussels: CIDESA, 1971 Nr. 2322, topic code 010)