Comparison of Indirect Sources of Efficacy Information in Pretesting Messages for Campaigns to Prevent Drunken Driving

Abstract

Enabling publics to remove the constraints that prevent health enhancement is the focus of much scholarly research and professional practice. This experiment tested the impact of 2 forms of symbolic modeling and verbal persuasion on self-efficacy beliefs and intentions to prevent a friend from driving drunk. Three efficacy-enhancing public service announcements tested participants' beliefs in their confidence to intervene successfully. As predicted, behavioral and verbal modeling engendered greater perceived self-efficacy and behavioral intentions than did verbal persuasion, with behavioral modeling registering the greatest effects. Implications for designing campaigns of self-directed change to prevent drunken driving among college students are discussed, as well as possible directions for research on self-efficacy and the situational theory of publics.

Notes

¹Early thinking about the effects of mass communication was rooted in theories of mass society, which, in part, held that the impersonality of such societies impeded the development of strong social ties, or relationships, leaving individuals psychologically isolated from each other and social institutions. Mass communication was seen as one of the primary means of uniting the masses and providing a stable system of social control. It was believed that mass-mediated messages affected the mass audience, or general public, uniformly because of inherited biological mechanisms explained by instinct psychology, which was at its height. Mere exposure was thought to lead directly to behavior change. It was against this intellectual backdrop that Edward L. Bernays and Carl Byoir conducted propaganda campaigns for the Committee on Public Information during World War I, according to what Grunig and Hunt (1984) have called the two-way asymmetrical model of public relations. Bernays (1923) later discussed his use of the principles of mass persuasion during peacetime in his seminal Crystallizing Public Opinion.

²Although the PSAs targeted moderate drinkers, analyses were performed on data for the entire sample of drinkers and nondrinkers, because there is no commonly agreed on definition of moderate drinking shared by this age group. In the absence of such a universal definition, it is possible that light and heavy drinkers consider themselves moderate drinkers. Indeed, this was a key finding in the formative evaluations cited earlier. It also is possible that nondrinkers might identify with the moderate-drinker spokesperson in the PSAs, because he espouses a drinking philosophy similar to theirs. Use of incorrect labels to connote college-student drinking is likely to cause audience selectivity problems, including source derogation (Milgram & Anderson, 2000). Hence, all types of drinkers were included in the sample. A subsequent investigation will report findings for a subsample of moderate drinkers.

³Standardized pretesting questions developed by agencies of the U.S. Department of Health and Human Services have been used for more than 20 years and include such measures as main-idea recall, comprehension, believability, personal relevance, and identification of strong and weak, as well as offensive, message elements. The data reported here suggest that formative researchers should also assess perceived self-efficacy when health messages are designed to instill confidence to adopt recommended preventive behaviors.

⁴According to DeVellis (2003), an alpha between .65 and .70 is “minimally acceptable” for preliminary research that uses original scales and one below .60 is “unacceptable” (p. 95), although it is not unusual to find alphas lower than .70 in published research. Indeed, Grunig and Grunig (1992, p. 294) noted that it is common to find alphas of .50 to .65 reported in communication research. More recently, Hon and Grunig (1999) concurred with DeVellis in their guidelines for measuring organization–public relationships, stating that an alpha below .60 is not reliable. Although he does not say why, Nunnally (1978) recommended .70 as the cutoff level. Neither DeVellis nor Nunnally justified their recommendations on theoretical or empirical grounds.

Note. BM = behavioral modeling ( .n = 66); VM = verbal modeling (n = 60); VP = verbal persuasion (n = 60); C = control (n = 55).

^a N = 241.

^b One-tailed significance.

∗p ≤ .025. ∗∗p ≤ .01. ∗∗∗p ≤ .001.