An Examination of Message Effects on Blood Donation: A Test of the Theory of Reasoned Action

A 2 x 2 x 2 factorial quasi-experimental design was used to measure the effects of three different types of persuasive messages on cognitive and normative beliefs about blood donation. The messages were designed to enhance positive beliefs, reduce the strength of negative beliefs and enhance normative beliefs regarding the act of donating blood. The persuasive messages were sent out to 254 randomly selected student subjects, split into the eight different groups specified by the factorial design. The impact of persuasive communication on beliefs about blood donation was found to be the highest in the case of normative beliefs. Small interaction effects were also found. Most interestingly, the cognitive structure construct, treated in earlier studies as a unidimensional construct, was found to break into four cognitive dimensions. The separate effects of each of these dimensions on attitudes toward blood donation were examined. Cross-over effects were found to occur between cognitive structure dimensions and subjective norms and between normative structure and attitude. Significant interaction effects were also found between attitude and subjective norms. Behavioral intention was predicted through attitude and subjective norms; however, unlike previous studies, behavioral intention did not appear to have any effect on actual behavior