Do bibliometrics introduce gender, institutional or interdisciplinary biases into research evaluations?

Systematic evaluations of publicly funded research sometimes use bibliometrics alone or bibliometric-informed peer review, but it is not known whether bibliometrics introduce biases when supporting or replacing peer review. This article assesses this by comparing three alternative mechanisms for scoring 73,612 UK Research Excellence Framework (REF) journal articles from all 34 field-based Units of Assessment (UoAs) 2014–17: REF peer review scores, field normalised citations, and journal average field normalised citation impact. The results suggest that in almost all academic fields, bibliometric scoring can disadvantage departments publishing high quality research, as judged by peer review, with the main exception of article citation rates in chemistry. Thus, introducing journal or article level citation information into peer review exercises may have a regression to the mean effect. Bibliometric scoring slightly advantaged women compared to men, but this varied between UoAs and was most evident in the physical sciences, engineering, and social sciences. In contrast, interdisciplinary research gained from bibliometric scoring in about half of the UoAs, but relatively substantially in two. In conclusion, out of the three potential sources of bibliometric bias examined, the most serious seems to be the tendency for bibliometric scores to work against high quality departments, assuming that the peer review scores are correct. This is almost a paradox: although high quality departments tend to get the highest bibliometric scores, bibliometrics conceal the full extent of departmental quality advantages, as judged by peer review. This should be considered when using bibliometrics or bibliometric informed peer review.