viii, 67 leaves : ill. ; 29 cm.Includes abstract and appendices.Includes bibliographical references (leaves 58-62).Two studies were conducted to test the effects of need for cognition, self-efficacy, stage of change, and reasons for smoking on the relationships between message framing, intentions to quit and message strength. In the first (pilot) experiment, a sample of 44 non-smokers and 14 smokers completed need for cognition, self-efficacy and stage of change measures and were randomly assigned to either the gain- or loss-framed condition. Although some significant effects were found, none of the hypotheses were supported. In the second study, 39 smokers completed the same measures in addition to a smoking motives and an affect measure. Message framing and perceptions of the prototypical smoker were manipulated, and participants were randomly assigned to one of four conditions. Again, some significant effects were found, but none of the hypotheses were supported. Limitations, including lack of power, and future research directions are discussed