Examining the persuasive effect of statistical messages: A test of mediating relationships

The current study tested the degree to which the sample size heuristic (Baesler & Bur goon, 1994), perceived verifiability of evidence (Ah Yun & Massi, 2000), and perceived message credibility (Kopfman, Smith, Ah Yun, & Hodges, 1998) mediate the relationship between the use of statistical evidence in a persuasive appeal and a person's attitude toward a given topic. Four hundred eighty‐six participants were exposed to one of three messages (statistical, narrative, or no‐evidence control) or a no‐message control condition and completed either a 12‐ (control) or 33‐item (experimental) survey that was designed to measure respondents’ perceptions of the sample size heuristic, verifiability of evidence, message credibility, and attitude toward a year‐round academic schedule. Path analysis and hierarchical regression modeling were employed to test the proposed model. Results revealed that the perceived sample size heuristic, verifiability of evidence, and message credibility mediate the relationship between statistical evidence and individuals’ attitudes. Additionally, the perceived sample size heuristic was found to be the strongest unique predictor of attitudes and confirmatory factory analysis results indicated that perceived verifiability and message credibility may be two indicators of a higher‐order factor. These findings and their implications for future research are discussed.