Conflicting health-related scientific evidence in news reports: effects of presentation format and hedging on perceived issue uncertainty and source credibility

Abstract

This study examined the effects of two journalistic practices in reporting conflicting health-related scientific evidence on journalists’ and scientists’ credibility and whether the effects were mediated by perceived issue uncertainty. The two practices examined were presentation format and hedging. When conflicting findings are reported, journalists can use either a one-article format, using one story to report the conflict, or a two-article format, using two stories with each story representing one side of the conflict. When conflicting findings are reported, journalists can use hedging (e.g., reporting the limitations of scientific studies) to present the conflicting information. An online experiment was conducted to examine the two journalistic practices’ effects. Results include the following: 1) the one-article format was beneficial to journalists’ competence, but detrimental to scientists’ competence, as compared with the two-article format; 2) journalists’ and scientists’ credibility in the hedged news conditions did not differ from those in the non-hedged news conditions; and 3) perceived issue uncertainty did not mediate presentation format’s or hedging’s effects on journalists’ or scientists’ credibility. An exploratory follow-up mediation analysis found that perceived message believability mediated presentation format’s effects on journalists’ and scientists’ credibility. Theoretical, practical, and methodological implications are discussed.