#602: When YouTube Meets Scientific Consensus: Laypeople’s Evaluation of Reliable and Alternative-Perspective Health Information

This study investigated how (1) emphasizing scientific consensus in reliable text-based information and (2) the modality of alternative-perspective health information influence laypeople’s information evaluation. A 2×2 factorial experiment was conducted with 178 undergraduates who read a reliable document about diabetes treatment with or without consensus messaging, and then either watched a video or read alternative-perspective information from YouTube. Results showed that when participants watched the YouTube video, those who read the document with the consensus messaging rated it higher for both epistemic and practical purposes and perceived it as more trustworthy. However, consensus messaging did not significantly affect their evaluation of evidence strength or possible treatments. These findings suggest that explicitly emphasizing scientific consensus enhances perceived reliability of expert information in multimodal contexts; however, it does not necessarily deepen understanding of why consensus reflects stronger evidence. Educational implications for fostering epistemic understanding of scientific consensus were discussed.