Why Scopus has introduced SciMago JR and SNIP
This paper introduces two journal metrics recently endorsed by Elsevier’s Scopus: SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP). SJR weights citations according to the status of the citing journal and aims to measure journal prestige rather than popularity.
It presents the main features of the two indicators, comparing them one with another, and with a journal impact measure similar to Thomson Reuters’ journal impact factor (JIF).
The journal impact factor, developed by Eugene Garfield as a tool to monitor the adequacy of coverage of the Science Citation Index, is probably the most widely used bibliometric indicator in the scientific, scholarly and publishing community. However, its extensive use for purposes for which it was not designed has raised a series of criticisms, all aiming to adapt the measure to the new user needs
In January 2010, Scopus endorsed two such measures that had been developed by their partners and bibliometric experts SCImago Research Group, based in Spain (…), and the Centre for Science and technology Studies (CWTS), based in Leiden, Netherlands, (…). The two metrics that were endorsed are SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP).
Compared to other main fields, life sciences and health sciences tend to reveal the highest SJR and RIP values. Compared to the basic, JIF-like RIP (raw impact per paper), SJR tends to make the differences between journals larger, and enhances the position of the most prestigious journals, especially – though not exclusively – in life and health sciences.
The fact that Scopus introduced these two complementary measures reflects the notion that journal performance is a multi-dimensional concept, and that there is no single ‘perfect’ indicator of journal performance.
Lisa Colledge, Félix de Moya‐Anegón, Vicente Guerrero‐Bote, et al. SJR and SNIP: two new journal metrics in Elsevier’s Scopus. Serials: The Journal for the Serials Community.Volume 23, Number 3 / November 2010. Pages: 215 – 221