peer review. To get an idea of the uncertainty in peer review, we rely on a model to bootstrap peer review outcomes. We conclude that particularly in Physics, Clinical Medicine, and Public Health, metrics agree quite well with peer review and may offer an alternative to peer review.'
author:
- 'V.A. Traag'
- 'L. Waltman'
bibliography:
- 'bibliography.bib'
title: Systematic analysis of agreement between metrics and peer review in the UK REF
---

Introduction
============

Many countries have some form of a national research assessment exercise in which universities and other research institutions are evaluated [@Hicks2012]. In part, such assessments aim to account for the expenses of public funds, but sometimes they also function to distribute funds based on performance. Scientific quality or scientific impact plays a central role in many assessment exercises [@Zacharewicz2018], but institutions may also be evaluated on other performance dimensions, such as their societal, cultural, and economic impact. Here, we restrict ourselves to scientific quality or scientific impact determined based on the publication output of an institution. However, we acknowledge that other dimensions may also play a critical role.

How the quality or impact of publications is assessed differs from country to country. Some countries have 