Impact factor, Scimago Indexes and the Brazilian journal rating sytem: where do we go from here?

As we approach a new period of evaluation of Brazilian Graduate Programs by the Ministry of Education, it seems appropriate to revisit the rating systems for scientific journals. According to the Ulrich’s Periodicals Directory, there are about 300,000 scientific periodicals in the world today. However, 270,000 of these are not subject to the process of peer review, meaning that only 30,000 journals should be taken seriously. Two major rating systems exist in the world: the Journal of Citation reports issued by ISIThomson and the SCImago indexes issued by Elsevier. The Journal of Citation Reports of ISI Thomson (JCRISI) has been publishing Impact Factors (IFs) for its collection of scientific journals for a few decades. More recently, SCImago began publishing Cites/Document (C/D) for its own collection of journals. The calculations to determine IFs and C/Ds are very similar. Briefly, the IF or the C/D for any journal “J” in any year “N” is given by the following equation: