Testimonials versus informational persuasive messages : the moderating effect of delivery mode and personal involvement

Abstract

Health communications use factual information or/and personal testimonials to inform and influence individual decisions that enhance health. Increasingly, Web and other computer-based systems are being used to communicate with patients. This study aims to test the relative effectiveness of testimonials compared to simple informational health messages presented through different modalities, and to the recipients with different levels of involvement. Results of the three independent experiments demonstrate that testimonials are more persuasive when presented through the audio mode rather than when presented through the written mode. Also, the informational messages are more persuasive when perceived by individuals characterized by high rather than low involvement and high rather than low need-for-cognition. The results are explained in terms of the Elaboration Likelihood Model (ELM). The interactive effect of transportation (Green & Brock, 2004) and involvement on persuasion is further examined. The findings help in developing the more effective ways of computer-based health communication. The highest level of efficiency can be achieved if the appropriate media modality and message format are used for recipients with certain initial involvement or need-for-cognition.