The impact of argument quality, source credibility, risk perception and visual design on perceived message effectiveness in covid-19 vaccine communication in Sweden: A quantitative study from an ELM perspective

Abstract: Reaching intended effects of the covid-19 pandemic vaccination is dependent on both coverage rates and time. Without vaccine mandates in Sweden, communication strategists have become essential to succeed. Vaccine hesitancy is complex with reasons differing on an individual level. This makes mass communication suboptimal, but also mainly what is used due to practical reasons. Consequently, understanding how mass communication about covid-19 vaccination is perceived and what impacts the perception, is useful for current evaluation and improvement of future communication strategies. Health and risk communication are in need of theoretical integration and extending empirical studies in real outbreak situations in the European context. Evaluation research has been criticized for not basing materials on theory. Without increasing the understanding of the mechanisms behind why some communication strategies work and why some do not, it is hard for authors to develop conclusive research and practitioners to translate evidence into action. Consequently, the thesis presented an interdisciplinary study using the information processing theory of the Elaboration Likelihood Model (Petty & Cacioppo, 1986) as framework. A quasi-experimental online survey was used to fulfill the aim of increasing the understanding about how argument quality, source credibility, visual design and risk perception influence the perceived effectiveness of a health risk message regarding vaccination in the context of covid-19. Through an extensive literature review of health communication and risk communication, these factors were identified as central to the context, along with control variables included. A moderated hierarchical regression was used as the analysis method on a sample of 319 Swedes. The full model was able to explain 63% of the perceived message effectiveness. The results showed significant contributions of the perceived argument quality (β=.62), source credibility (β=.20) and prior attitude towards covid-19 vaccination (β=.10). However, the perceived personal risk of covid-19 did not prove to motivate an increased extent of elaboration, as hypothesized. Furthermore, the visual design did not improve the perceived message effectiveness, nor interact with perceived argument quality and perceived source credibility. The results suggest that in this context, strategic communicators can impact the message effectiveness and the priority should be on the quality of arguments. This is important since it is a factor that the practitioner does have control over. In comparison to argument quality and expectations from literature, source credibility contributed relatively little to the perceived message effectiveness. It was also unexpected that the results indicated that another factor than the perceived personal risk of covid-19 may be key in motivating elaboration. Due to this, the study was not able to demonstrate support for the ELM in this context. Altogether, this stresses the importance of extending interdisciplinary empirical research, combining theory on message effects, information processing and behavior change in health and risk communication.