Thematic and Geographical Diversity of JCR, SJR and CORE: Towards a New Expanded Journal List

Abstract Purpose This study has a threefold goal: 1) to compare the thematic and geographical diversity of the JCR, SJR and CORE source lists; 2) to discuss the need for dual classification, i.e., publication classification and journal classification, for enhanced research evaluation results; 3) to present the Expanded Journal List (EJL), which enlarges the number of sources available for research evaluation analyses and produces more-robust results. Design/Methodology/approach This paper uses a list selection process similar to the methods used in previous works. The main differences are the incorporation of CWTS’s CORE and the use of the ISSN Network instead of Ulrich’s Periodicals Directory. The data available in October 2024 were downloaded from the lists of journals in Clarivate’s SCIE, SSCI, AHCI and ESCI indices, Scopus’ extended list and CWTS’s list of CORE sources. The OpenAlex data are from the June 2024 snapshot. Findings The results show a strong geographical and thematic bias in CORE, caused by the exclusion of publications in languages other than English. Furthermore, the new proposed list presents a 30 % increase in the number of sources, a significant increase in the number of countries and a more balanced representation of scientific areas. Research limitations The analysis presented here is based on a detailed harmonisation of the scientific areas in each of the lists. However, this approach is insufficient. A rigorous, specific classification is needed to enable full thematic assignment based on OpenAlex publications. Practical implications The combination of more sources and a larger number of countries in EJL will allow more comprehensive and diverse analyses of the international scientific scene. Originality/value This paper offers two new features. It is the first study to analyse the CORE list based on the methodology used by the Leiden Ranking over the last 10 years. The second is that it proposes the largest list of sources prepared to date. It also offers a necessary update of the analyses of sources on the JCR and SJR lists, revealing significant changes since the reports given by previous literature.