A field experiment investigated the use of interactive cable television to deliver in-service instruction to elementary school teachers. Fifteen schools in Rockford, Illinois, were designated as controls, 12 were equipped for one-way television, and 14 were set up for two-way communication. A consultative relationship with teachers was established through the Client-Centered Production System (CCPS), which provided for teacher input via interviews, group meetings, and a committee which worked with investigators in the selection of relevant topics and design of the programs to be produced. In interviews conducted after the showing of the eight shows, 35 percent of the teachers in the control schools reported that they had learned new teaching ideas during the year, as compared with 53 percent in the one-way communication schools and 69 percent of those with two-way communication. On the basis of these findings and cost/benefit analyses, it was concluded that the project delivered a greater variety of teaching innovations than could be presented in an equivalent amount of time by conventional means, and at about the same cost. Limitations of the experimental design are discussed, as well as implications of the findings for policy decisions. Supporting materials appended include synopses of the programs and copies of interview questionnaires. (LLS)