Public service communication source influence and radio gatekeeper behavior : a controlled field experiment

Hypotheses were derived from a theory of source valence, or source effects, originated by Herbert Kelman. This theory separated receiver response to source influence into three separate processes: compliance, identification and internalization. In essence, a subject complies with a source who has control, a subject identifies with a source who is attractive, and a subject internalizes the cause of a source with credibility, all of which would result in source-to-subject influence.

The field experiment revolved around the Innovation Center—a government-sponsored, nonprofit organization created to provide commercialization assistance to small time inventors. The Innovation Center is headquartered in Knoxville, Tennessee and is chartered to serve the Appalachian region of Tennessee which is approximately the eastern half of the state.

The experimental subjects were gatekeepers at the ninety radio stations in eastern Tennessee. A comparative treatments controlled field experiment was conducted to test the Kelman-based hypotheses Ill concerning a request from the Innovation Center to air public service advertisements (PSAs) and subsequent radio gatekeeper behavior. The ninety stations were randomly assigned into four groups. Compliance, identification and internalization source effects treatments were administered to three groups while the remaining group received a placebo treatment. The four treatments were operationalized through cover letters accompanying the Innovation Center's public service campaign package—all other elements were held constant while the author and content of cover letters was varied. The dependent variable was the actual niimber of airings granted the PSAs as later determined by station log book records in response to self-administered, mailed questionnaires.

A major finding was the existence of significant differences among the treatment groups in extent of PSA airing. The compliance treatment elicited a far larger number of total airings followed in order by identification, placebo, and intemalization treatments. An additional finding regarded the time slot placement of public service announcements. Untrue to the conventional belief that PSAs are relegated to undesirable time slots (e.g., late at night), the Innovation Center's PSAs received equitable placement in all time slots with an inclination toward more desirable time slots. Slight differences in time slot placement among treatment groups were noted.

From a practical standpoint these findings indicate a possible means by which PSA sources can increase message airings—a variable over which broadcasters have control. From a research standpoint this IV study makes an incremental contribution to much needed research and theory development in public service communication. Also, the procedures used in operationalizing Kelman's communication theory to this specific research setting will aid in the successful future application of Kelman's approach to other situations.