Written by Claus Rosenkrantz Hansen

… this time around, however, things are a bit different. Scopus has listened to experts and critics, or so they claim and has developed a new and cutting-edge methodology for CiteScore calculations.  
Every year sees the release by Scopus and Web of Science of new editions of CiteScore and Journal Impact Factor (JIF), their journal metrics.
Until now, the main difference between the two metrics has been the volume of journals covered, with the vast majority of journals relevant to CBS having a CiteScore (roughly 8000 relevant journals) compared to JIF, which comprises 900 relevant journals.

CiteScore reinvented
With the recent release of the new lists, the difference has increased. Scopus has re-engineered CiteScore in an attempt to make the metric more ”clear, current, comprehensive and free” – to use Scopus’ own description of the new methodology.

The main features can be summarized in this way (click the image on the right-hand side to view the illustration):

  • Only peer-reviewed publications (articles, reviews, conference papers, book chapters, and data papers) are included. Previously, all publications were included in the calculations – also non-peer-reviewed article types like editorials, news items, letters, and notes.
  • Four-year citation window: Citations are now counted cumulatively from the year of publication until the end of the calculation window (up to four years). In the past, citations were counted for the previous year only. A four-year window provides a more complete indication of citation patterns for fields such as SSH that traditionally are characterized by longer citation periods.
  • Publications in the four years up to and including the calculation year will now be included. This means that CiteScore can be calculated for journals with just a single year of publication.
  • CiteScore values will be displayed to one decimal place in order to avoid an impression of precision, in line with industry best practice.

CiteScore values date back to 2011, and to make the data comparable across time, all years have been calculated in accordance with the new methodology.

Don’t forget about JIF
It is not all about CiteScore, however. Web of Science just published their annual Journal Impact Factor, which methodologically is not very different from last year.

Thus, JIF remains a two-year impact factor, because it has been calculated on the basis of citations to articles that have been published in the previous two years (cf. illustration).
Even if JIF pretty much looks the same, it is relevant to raise a few points:  

  • 283 new journals have been included. Of these 108 are golden Open Access journals.  
  • 17 journals (or the equivalent of 0.14% of the total volume) have been excluded from the list and so remain JIF-less due to suspicious citation patterns (excessive journal self-citation).

Learn more about CiteScore and Journal Impact Factor, and find out how to locate them, in the CBS Library guide to Research Metrics.

For more information, please contact the Research Metrics Team