Television can be used in the service of informal education, or more formally in schools and colleges. This article deals with the educational problems raised by the latter use. Those problems will only be solved when scientists in general take the medium seriously enough to master its techniques of communication and to co-operate in assessing its impact. Its powers and limitations, which are not basically different from those of film, can already be discerned in broad outline. The ways in which it is being developed in different countries depend not only on the qualities of the medium but on their differing educational systems. In this country the emphasis is on the help which television can give to the teacher at all levels rather than on the possibility of replacing him. The nature of that help must be determined in the light of educational purposes.