Research groups: how big should they be?
- Published
- Accepted
- Subject Areas
- Science and Medical Education, Science Policy, Statistics
- Keywords
- research group, impact factor, citations, productivity
- Copyright
- © 2015 Cook et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Research groups: how big should they be? PeerJ PrePrints 3:e812v1 https://doi.org/10.7287/peerj.preprints.812v1
Abstract
We have investigated the relationship between research group size and productivity in the life sciences in the United Kingdom using data from 398 principle investigators (PIs). We show that the number of publications increases linearly with group size, but that the slope is modest relative to the intercept, and that the relationship explains little of the variance in productivity. A comparison of the slope and intercept suggests that PIs contribute on average 5-times more productivity than an average group member and using multiple regression we estimate that post-doctoral researchers are approximately 3–times more productive than PhD students. We also find that the impact factor and the number of citations are both non-linearly related to group size such that there is a maximum. However, the relationships explain little of the variance and the curvatures are shallow so the impact factor and the number of citations do not greatly depend upon group size. The intercept is large relative to curvature suggesting that the PI is largely responsible for the impact factor and the number of citations from their group. Surprisingly we find this non-linear relationship for post-docs, but for PhD students we observe a slight but significant decrease in the impact factor. The results have important implications for the funding of research. Given a set number of Pis there is no evidence of diminishing returns in terms of the number of papers published and only a very weak cost to very large groups in terms of where those papers are published and the number of citations they receive. However, the results do suggest that it might be more productive to invest in new permanent members of faculty rather than additional post-docs and PhD students.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Supplementary Table S1
The anonymised data used in the analysis
