A preprogrammed over-the-air marketing research system includes transmission facilities for delivering a regularly scheduled television signal and a low power, microwave transmitter or satellite transponder for delivering a special over-the-air television signal, including substitute programming, to cooperating households. Each household has an antenna for receiving the special television signal, a down converter and a television control unit that includes a small household stored program computer. The computer receives in advance and stores a substitute programming schedule and other instructions for a broadcast period from a command and control computer, records the "on-off" condition of the television receiver and the channel being watched, and controls the condition of a three-way switch that enables members of a particular household to view the normal television signal or substitute programming from the special television signal or text or music from the household computer in accordance with the stored schedule. In this manner, the command and control computer establishes test panels consisting of one or more cooperating households in advance by instructions transmitted to each household computer by the command and control computer. Responses of cooperating households to marketing research tests may be obtained from automatic household purchasing response apparatus installed in each cooperating household or from cooperating retail stores and are transmitted to the command and control computer for analysis.