From amazing work to I beg to differ - analysis of bioRxiv preprints that received one public comment till September 2019

While early commenting on studies is seen as one of the advantages of preprints, the nature of such comments, and the people who post them, have not been systematically explored. We analysed comments posted between 21 May 2015 and 9 September 2019 for 1,983 bioRxiv preprints that received only one comment. Sixty-nine percent of comments were posted by non-authors (n=1,366), and 31% by preprint authors (n=617). Twelve percent of non-author comments (n=168) were full review reports traditionally found during journal review, while the rest most commonly contained praises (n=577, 42%), suggestions (n=399, 29%), or criticisms (n=226, 17%). Authors’ comments most commonly contained publication status updates (n=354, 57%), additional study information (n=158, 26%), or solicited feedback for the preprints (n=65, 11%). Our study points to the value of preprint commenting, but further studies are needed to determine the role that comments play in shaping preprint versions and eventual journal publications.