Are You Sure About That? Investigating the Effects of Endorsement Cues and Source Reputation on Credibility Evaluations and Knowledge Confidence in Short-format Videos

Social media platforms, particularly those with short-format videos like TikTok, have become a primary source of information. However, exposure to such content can lead to overconfidence in the correctness of one’s knowledge. This study (N = 200) examines how users’ knowledge, endorsement cues, and the sources’ reputation and familiarity influence their credibility judgments about short-format videos presenting scientific information. The results show that users base their credibility judgments not on endorsement cues but on the sources’ familiarity, reputation, and their prior knowledge confidence. While changes in both subjective and objective knowledge were not related to the perceived credibility of the videos, our findings indicate that watching short-format videos can enhance recipients’ confidence in their knowledge if they have the correct knowledge. These findings highlight the potential of social media platforms with short-format videos for science communication.