ABSTRACT
Thompson (1984) once noted that “too many researchers start from scratch rather than investigating variables that may moderate processes uncovered in earlier research” (p. 149). Heeding her wisdom, this chapter identifies and delineates the overlapping variables important in several mainstream health communication theories and models and places them within a message design framework. Some of the most commonly used theories that define how to create messages to motivate health-related behavior changes include the Health Belief Model (Janz & Becker, 1984; Rosenstock, 1974a, 1974b), the Theory of Reasoned Action (Fishbein & Ajzen, 1975; 1981), Social Cognitive Theory (also known as Social Learning Theory) (Bandura, 1977), the Theory of Planned Behavior (Ajzen, 1991), and the Extended Parallel Process Model (Witte, 1992a). Although some of these health behavior theories continue to be criticized for (a) excluding social and environmental factors, (b) utilizing a unidirectional flow of information without regard for interactivity, (c) lack of feasibility (e.g., political or financial), and (d) limited applicability to certain audiences (Hochbaum, Sorenson, & Loring, 1992), using the guidance of a theory in message design can save time, money, and resources.
