Proposes that before adopting a new health behavior an individual considers his vulnerability to the problem, the seriousness of the problem, and the effectiveness of the new behavior for reducing the risk or preventing the problem emphasizes that people and their environment interact continuously, each influencing the other considers an individual’s intention to change behavior to be determined by both personal attitudes and subjective norms focuses on the process by which an idea or behavior spreads throughout a population assumes that new behavior change involves a series of different steps through which people must move. a. theory of planned behavior b. health belief model. c. stages of change model. d. social cognitive theory. e. diffusion of innovation model.