Abstract
One of the most fundamental changes in human experience in the twentieth century has been the dissemination of radio and television throughout the world. Print media were the primary means of mass communication before this century. Radio and television differ fundamentally from print in part because they can be used and understood without the skill and effort of literacy and the extensive training required to achieve it. Therefore, they reach the young, the sensorially or intellectually handicapped, the learning disabled, the poor, the illiterate, and many others who would not be much influenced by print media.