The Effects of User Comments on Science News Engagement

Online sources such as social media have become increasingly important for the proliferation of science news, and past research has shown that reading user-generated comments after an article (i.e. in typical online news and blog formats) can impact the way people perceive the article. However, recent studies have shown that people are likely to read the comments before the article itself, due to the affordances of platforms like Reddit which display them up-front. This leads to questions about how comments can affect people's expectations about an article, and how those expectations impact their interest in reading it at all. This paper presents two experimental studies to better understand how the presentation of comments on Reddit affects people's engagement with science news, testing potential mediators such as the expected difficulty and quality of the article. Study 1 provides experimental evidence that difficult comments can reduce people's interest in reading an associated article. Study 2 is a pre-registered follow-up that uncovers a similarity heuristic; the various qualities of a comment (difficulty, information quality, entertainment value) signal that the article will be of similar quality, ultimately affecting participants' interest in reading it. We conclude by discussing design implications for online science news communities. © 2021 ACM.