THIS IS A COLLECTION OF CASE STUDIES ON THE USE OF TELEVISION, RADIO, FILMSTRIPS, AND CORRESPONDENCE STUDY--ALONE, OR IN COMBINATION--FOR INSTRUCTION, EDUCATIONAL EXTENSION, AND ADULT EDUCATION IN SIX COUNTRIES--ITALY (ETV), NIGER (RADIO AND RADIO PLUS FILMSTRIPS), NEW ZEALAND (RADIO PLUS CORRESPONDENCE), HONDURAS (RADIO), NIGERIA (ETV), AND USA (MPATI--AIRBORNE ITV). EACH STUDY RECOUNTS THE PROJECT'S HISTORY, ORGANIZATION, OPERATION, COSTS, AND EVIDENCE OF EFFECTIVENESS. THIS EVIDENCE IS BY AND LARGE FAVORABLE, THOUGH WITH THE EXCEPTION OF THE MPATI, LARGELY INCORRECT--BASED ON ATTITUDES OF PARTICIPATING TEACHERS AND RADIO CLUB LEADERS, IMPRESSIONS OF VISITORS, OR PROPORTIONS OF STUDENTS WHO PASSED LITERACY EXAMINATIONS OR WHO TRANSFERRED WITH NO DIFFICULTIES TO REGULAR SCHOOLS. THE COST ANALYSES REFLECT THE HIGH AND VARIABLE COSTS OF INTRODUCING AND MAINTAINING THE NEW MEDIA AND INCLUDE EXTRAPOLATIONS OF PRESENT COSTS TO THE OPTIMUM SITUATION WHERE THE ECONOMIES OF SCALE ARE EXPLOITED TO THE FULL. A RECURRENT THEME IN THE CASE STUDIES ON THE DEVELOPING COUNTRIES IS THE NEED TO INTERGRATE THE NEW MEDIA WITHIN THE EDUCATIONAL SYSTEM. MOST OF THE DIFFICULTIES NOTED SEEM TO STEM FROM THE SYSTEM'S INABILITY TO PROVIDE THE NECESSARY RESOURCE BASE. THIS DOCUMENT IS AVAILABLE FROM UNESCO, PLACE DE FONTENOY, 75 PARIS-7E, FRANCE, FOR $4.50. (GG)