The present study investigates the role of source characteristics, the quality of evidence, and prior beliefs of the topic in adult readers' credibility evaluations of short health-related social media posts. The researchers designed content for the posts concerning five health topics by manipulating the source characteristics (source's expertise, gender, and ethnicity), the accuracy of the claims, and the quality of evidence (research evidence, testimony, consensus, and personal experience) of the posts. After this, accurate and inaccurate social media posts varying in the other manipulated aspects were programmatically generated. The crowdworkers (N = 844) recruited from two platforms were asked to evaluate the credibility of up to ten social media posts, resulting in 8380 evaluations. Before credibility evaluation, participants' prior beliefs on the topics of the posts were assessed. The results showed that prior belief consistency and the source's expertise affected the perceived credibility of the accurate and inaccurate social media posts the most after controlling for the topic of the post and the crowdworking platform. In contrast, the quality of evidence supporting the health claim mattered relatively little. The source's gender and ethnicity did not have any effect. The results are discussed in terms of first- and second-hand evaluation strategies.

翻译：本研究探讨了来源特征、证据质量和读者对话题的先验信念在成年读者评估健康类社交媒体短帖可信度中的作用。研究者围绕五个健康话题设计帖子内容，通过操纵来源特征（来源专业性、性别和种族）、主张的准确性以及证据质量（研究证据、证词、共识和个人经验）来构建帖子素材。随后，程序化生成了这些准确与不准确、且其他操纵维度各异的社交媒体帖子。从两个平台招募的众包工作者（N=844）需评估至多十篇社交媒体帖子的可信度，共计产生8380次评估。在进行可信度评估前，研究者评估了参与者对帖子话题的先验信念。结果表明，在控制帖子话题和众包平台因素后，先验信念一致性与来源专业性对准确与不准确社交媒体帖子感知可信度的影响最为显著。相比之下，支持健康主张的证据质量影响相对较小。来源的性别和种族未产生任何效应。本研究从第一手与第二手评估策略的角度对结果进行了讨论。