The Research Excellence Framework is a system to assess the quality and quantity of research outputs from Higher Education Institutions in the UK.
This exercise happens every few years: the last REF took place in 2014 and the next one is taking place in 2021.
This blog post explains how it works in detail.
All staff on academic contracts are eligible to be included in REF 2021. Outputs are reviewed and marked by Units of Assessments according to discipline. This official paper gives detailed guidance on staff and outputs.
The Stern Review is a review on the REF commissioned by the UK government and published in 2016.
This review concludes that bibliometrics is an important tool to assess the impact and quality of research outputs (see paragraph 76 and section on Assessment of outputs), but should be used in conjunction with peer review and should not based on one kind of metrics alone.
This review support the Open Access movement. Visit our page on Open Access for more information,