Stevan Harnad alerted me earlier this year that Elsevier is a fully green open access publisher. Authors can archive pre-print or post-print copies (the one exception for Elsevier, according to SHERPA/RoMEO, is The Lancet: only a word-processed version of a peer-reviewed, accepted, and edited article from The Lancet can be placed on a personal or institutional websites, any time after publication.) One of the largest biomedical journal publishers providing authors with these green options has certainly added momentum to the green open access movement.
It was a therefore a revelation for me to discover Elsevier’s SCImago Journal Rank (SJR), a free tool to compare the citation data of the more than 15,000 peer-reviewed journals indexed by the Elsevier SCOPUS database since 1996. SCOPUS is part of the new SciVerse umbrella (hub) and prohitively expensive for many colleges and universities. The word on SJR has not traveled very fast, and I will try to accelerate knowledge of this tool in my own environment.
How does this tool compare with the very well know subscription product Journal Citation Reports (JCR)? The Elsevier Bibliometrics page which offers a succinct comparison with Thomson Reuters’ JCR. Here are the major points:
- Five year Impact Factor: Instead of counting citations in the previous two years and dividing by source items in those years, as JCR does, SJR citations are counted in the previous five years and again divided by the source items published in the previous five years. Five years may be more appropriate for journals where it may take longer than two years to disseminate and respond to published works, as well as present more consistent year-t0-year variation.
- Journal rank within a subject category may be different when using a two or a five year impact factor, so care is needed when assessing ranked lists to describe which metric is being utilized.
- SCImago Journal Rank, conceptually similar to the Impact Factor, uses a different scale, assigning each citation a value greater or less than one based on the rank of the citing journal. Detailed methodology is available here.
- The broader and deeper set of data from SCOPUS provides additional types of searching analysis: country ranks, country and regional comparisons, and maps oof co-citation relationships.
- The use of SCOPUS data brings many more open access journals into journal analysis and comparison.
Rather than needing to tell you, the absence of a subscription barrier means that you can just jump right in and try it.
Yes, I feel a little late to the party, as there have been several articles looking at this new resource.