Aggregated journal-journal citation relations in Scopus and Web-of-Science matched and compared in terms of networks, maps, and interactive overlays

TL;DR

This study compares aggregated journal-journal citation networks from Scopus and JCR, analyzing their similarities, differences, and coverage, revealing that JCR has denser networks while Scopus covers humanities better.

Contribution

It provides a detailed comparison of journal citation networks in Scopus and JCR, including network structure, coverage, and overlay mapping, highlighting differences and similarities.

Findings

JCR network is denser and more connected than Scopus.

High correlation in journal rankings (Spearman's rho > 0.97).

Scopus covers humanities journals better than JCR.

Abstract

We compare the network of aggregated journal-journal citation relations provided by the Journal Citation Reports (JCR) 2012 of the Science and Social Science Citation Indexes (SCI and SSCI) with similar data based on Scopus 2012. First, global maps were developed for the two sets separately; sets of documents can then be compared using overlays to both maps. Using fuzzy-string matching and ISSN numbers, we were able to match 10,524 journal names between the two sets; that is, 96.4% of the 10,936 journals contained in JCR or 51.2% of the 20,554 journals covered by Scopus. Network analysis was then pursued on the set of journals shared between the two databases and the two sets of unique journals. Citations among the shared journals are more comprehensively covered in JCR than Scopus, so the network in JCR is denser and more connected than in Scopus. The ranking of shared journals in terms of indegree (that is, numbers of citing journals) or total citations is similar in both databases overall (Spearman's \r{ho} > 0.97), but some individual journals rank very differently. Journals that are unique to Scopus seem to be less important--they are citing shared journals rather than being cited by them--but the humanities are covered better in Scopus than in JCR.