Facts do not speak for themselves: Community norms, dialog, and evidentiary practices in discussions of COVID-19 on Reddit.

The present study sought to explore the distinct discourse norms and evidentiary practices in discussions of COVID-19 in four subcommunities on Reddit. Qualitative analysis found that communities differed in the degree to which they reinforce and augment Reddit's platform-wide norms for dialog and evidence use. One of the three communities (r/AskTrumpSupporters) differed from the rest by establishing discourse norms for turn-taking between politically opposed users and structuring dialog around authentic questions aimed at understanding alternative points of view. Quantitative analyses revealed that this community significantly differed from the other communities in the proportion of dialogic exchanges and in the use of evidentiary practices (sourcing, source evaluation, and interpretation of evidence). Excerpts of dialog from this community are used to illustrate findings. We conclude with implications for educators interested in preparing youth to critically engage with scientific information they encounter in public discourse.