Influence of interdisciplinarity on peer-review and bibliometric evaluations in physics research

It is often argued that interdisciplinary research is valued less in both qualitative (peer-review based) as well as in quantitative (bibliometric) assessments. A recent extensive, nation-wide evaluation of all academic physics groups in the Netherlands allowed us to investigate this problem empirically. Therefore, we first developed an operationalization of ‘interdisciplinarity’. On the basis of our findings, we refute the above statement, at least for the field and the country involved. We found that (i) peer judgements do not significantly correlate with the degree of interdisciplinarity; (ii) only elementary bibliometric indicators correlate negatively, but (iii) ‘advanced’ indicators do not correlate with the degree of interdisciplinarity, except a small correlation in the case of large programs. Thus, we found no general evidence for a peer-review bias as well as a bibliometric bias against interdisciplinary research.