She found similarly high correlations when studying Chemistry, Computer Science, and Business & Management separately. The high correlations can be partly explained by the use of a size-dependent perspective. We comment on this in Section \[sec:size\_dependent\].

Data and Methods
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The REF 2014 provides a well-documented dataset of both the evaluation results and the submitted publications that have been evaluated[^7]. The REF 2014 has different scores for different profiles: “output”, (societal) “impact”, and “research environment”. Only the “output” profile is based on an evaluation of the submitted publications. The others are based on case studies and other (textual) materials. We restrict ourselves to the REF 2014 scores in the output profile, and we compare them with citation metrics.

We match publications to the CWTS in-house version of the Web of Science (WoS) through their DOI. We use the Science Citation Index Expanded, the Social Sciences Citation Index, and the Arts & Humanities Citation Index. Most publications are articles (type ‘D’ in the REF 2014 dataset), but the publications also include books, conference proceedings, and other materials. In total, $190\,962$ publications were submitted, of which $149\,616$ have an associated DOI, with $133\,469$ of these being matched to the WoS. Overall, the 