Every year Thomson Scientific - last week renamed as Thomson Reuters – publishes the new impact factors in june/july in the Journal Citation Reports (JCR). The impact factor is almost certain the best known and most used index for measuring the impact of scientific journals. There are more than 6100 journals wich are followed by Thomson in the Science edition of the JCR and from which the articles are indexed in the Web of Science.
Since a few years the publisher Elsevier has its own counterpart of the Web of Science, Scopus that is. Unfortunately we do not have access at K.U.Leuven to this extensive citation database. Nevertheless since the end of 2007, Spanish scientists from the SCImago Research Group from Granada have opened a portal with free bibliometric information and rankings from scientific journals (from Scopus), with the name: SCImago journal and country rank.
This website offers relevant data and information about scientific output (from approx. 13,000 journal titles) via journal rankings and comparisons, country rankings, country profiles, tables (with export formats for MS Excel) and diagrams or charts. The data are derived from the Scopus database (from 1996, in the fields of natural sciences, engineering, medicine and social sciences) and the calculation of their own created SCImago journal indicator is based on the Google PageRank algoritme (but they offer also other figures like the number of citations, documents etc.). They als offer the Hirsch index or h-index as an instrument to measure the impact of a journal or even a country.
Below an example of a bubble chart with the number of publications in Belgium, for the years 2005-2006, in the top28 Subject Categories (comparison of h-index and the average number of cites per document).
The categories from Scopus do not necessarily match exactly with those from the Web of Science or JCR. Nevertheless one can venture a comparison… Hereby a table with figures from the top 24 journals in the category ’Obstetrics and gynecology’, data from 2006.
Other: journal is indexed in another category by JCR / None: journal not indexed in JCR
The differences are not enormous but the opposite would be rather astonishing. ;-)
Moreover in this specific category the differences of the impact factors ins the JCR are not so distinct after the second title in rank.
Further readings: Comparison of SCImago journal rank indicator with journal impact facto. FASEB J. 2008 Apr 11 [Epub ahead of print]
From my sideline seat, Thompson Reuters seems awfully archaic…
Can someone please explain to me how and why Thompson Reuters Scientific has such a grip on scientific journal Impact Factors? If you look at the list of various indexing services, you can see that they are all brushed aside…
[...] the impact factors and rankings with SCImago journal indicators (data from Scopus). We wrote a previous entry about SCImago as an [...]