As presidents of the Brazilian Association for the Advancement of Science and the Brazilian Academy of Sciences, we object to your negative perspective on CAPES, our education ministry's agency for the Coordination for the Improvement of Higher Education Personnel (Nature 500, 510–511; 2013).

The impact factor is just one of a long list of indicators used by CAPES since 1976 to rate programmes in 48 fields of research, from social studies to physics. It is important to stress that the agency uses a system of peer review to evaluate and rank Brazil's graduate programmes — not to assess individual curricula vitae. The country's scientific community analyses data on the performance of each programme over the previous three years.

Other indicators that CAPES evaluates include recognition of faculty members' research by the international community; the coherence, consistency and comprehensiveness of the curriculum and infrastructure for teaching, research and continuing education; students' participation in research; and the contribution of faculty members to the supervision of doctoral students.

There are several ranking systems worldwide that also incorporate journal impact factors and citations into their metrics and are acknowledged by the scientific community. One is the Academic Ranking of World Universities (also known as the Shanghai Ranking), which inspired the Ranking Web (or Webometrics) for universities around the world.