The chart below compares the quality of research outputs assessed in the 2008 RAE and the 2014 REF. Impact was not assessed in the 2008 RAE, and there are significant differences in how the research environment was assessed between the two exercises, so these two elements are not compared.
A total of 191,150 outputs were submitted in the 2014 REF, compared to 215,507 outputs submitted in the 2008 RAE. The REF panels found significant improvement in the quality of outputs submitted in the REF. Across all submissions, 22% of outputs were judged to be world-leading (4*) in the REF, compared with 14% in the RAE. A further 50% were judged to be internationally excellent (3*) in the REF, compared to 37% in the RAE.
The improvement in output quality is consistent with the views of the international members of the REF main panels, and aligns with independent evidence of the enhanced international standing of UK research.
The chart below shows the increase in the number of outputs judged to be 3* and 4* in each exercise. This is compared with the increase in the number of highly cited papers produced by the UK over the same time-periods. Data on the number of highly cited papers has been provided by Scopus. Although the outputs submitted in the RAE and REF, and the set of papers included in the citation analysis are different, they both indicate a similar trajectory of improvement in the UK’s research performance. Over the RAE and REF time-periods:
The number of 4* outputs increased by 42%, and the number of outputs judged to be at least 3* increased by 24%.
The number of UK outputs in the top 1% of the world's most highly cited papers increased by 44%. The number of UK outputs in the top 5% increased by 31%, and the number of UK outputs in the top 10% increased by 29%.