The Journal Coverage of Web of Science, Scopus and Dimensions: A Comparative Analysis (2011.00223v2)

Abstract: Traditionally, Web of Science and Scopus have been the two most widely used databases for bibliometric analyses. However, during the last few years some new scholarly databases, such as Dimensions, have come up. Several previous studies have compared different databases, either through a direct comparison of article coverage or by comparing the citations across the databases. This article attempts to compare the journal coverage of the three databases: Web of Science, Scopus and Dimensions. The most recent master journal lists of the three databases have been used for the purpose of identifying the overlapping and unique journals covered in the databases. The results indicate that the databases have significantly different journal coverage, with the Web of Science being most selective and Dimensions being the most exhaustive. About 99.11% and 96.61% of the journals indexed in Web of Science are also indexed in Scopus and Dimensions, respectively. Scopus has 96.42% of its indexed journals also covered by Dimensions. Dimensions database has the most exhaustive coverage, with 82.22% more journals covered as compared to Web of Science and 48.17% more journals covered as compared to Scopus. We also analysed the research outputs for 20 highly productive countries for the 2010-2019 period, as indexed in the three databases, and identified database-induced variations in research output volume, rank and global share of different countries. In addition to variations in overall coverage of research output from different countries, the three databases appear to have differential coverage of different disciplines.

Journal Coverage of Web of Science, Scopus, and Dimensions: A Comparative Analysis

Overview

The paper "The Journal Coverage of Web of Science, Scopus and Dimensions: A Comparative Analysis" by Singh et al. conducts a thorough comparative paper of three prominent scholarly databases: Web of Science, Scopus, and Dimensions. These databases serve as significant tools for research assessment exercises in scientometric studies. This analysis involves a comprehensive examination of their respective journal coverages, variations in research output volume, rank, global share of research from different countries, and differences in subject area composition.

Key Findings

1. Journal Coverage:
   • Web of Science (WoS) exhibits a highly selective indexing approach, ensuring high-quality standards.
   • Scopus and Dimensions have more extensive journal coverage compared to WoS. Scopus covers 96.42% of its journals in Dimensions and 99.11% of WoS journals.
   • Dimensions stands out with the most exhaustive coverage, including 82.22% more journals than WoS and 48.17% more than Scopus.
2. Country-wise Research Outputs:
   • The research output volumes for selected countries show significant variations across the databases. For instance, the USA has 3.6 million records in WoS, which increases to 4.16 million in Scopus and 4.79 million in Dimensions.
   • The global share of research output for certain countries varies by as much as 10% across different databases. This indicates potential biases introduced by the choice of data source in research assessments.
   • The compounded annual growth rate (CAGR) for research outputs also differs, with Dimensions generally showing a higher CAGR compared to WoS and Scopus.
3. Subject Area Distribution:
   • The databases manifest distinctive coverage shares across various disciplines. Dimensions puts significant weight on Social Sciences and Arts & Humanities, which constitute 14.4% and 3.5% of its output, respectively, compared to 6.7% and 1.3% in WoS.
   • Scopus and WoS share a relatively similar distribution, emphasizing Life Sciences, Physical Sciences, and Technology.

Implications and Future Directions

The evident differences in coverage and disciplinary emphasis among Web of Science, Scopus, and Dimensions have several practical and theoretical implications. As researchers and institutions select a database for evaluation, their choice profoundly influences the perceived research output's volume, growth trends, and discipline-specific emphasis. This selection can significantly affect national research evaluation exercises, bibliometric studies, and strategic research planning.

1. Research Evaluation:
   • Policymakers and funding bodies should be cautious in using a single database for comprehensive research impact assessments due to observed variations.
   • A blend of databases might offer a more nuanced picture of the global and regional research landscapes.
2. Database Strategy:
   • For fields in Social Sciences and Arts & Humanities, Dimensions could be an invaluable resource due to its broader coverage.
   • New databases like Dimensions are challenging traditional databases by providing more inclusive and diverse journal lists, making them pivotal in evolving research evaluation frameworks.
3. Future Research:
   • An in-depth exploration of the inclusion policies and indexing guidelines of these databases can further elucidate the observed disparities.
   • Further, a bibliometric analysis of other publication types such as book chapters, conference proceedings, and preprints across these databases could offer a more comprehensive comparative perspective.

Conclusion

The paper effectively highlights the substantial differences in journal coverage among Web of Science, Scopus, and Dimensions, with the latter significantly leading in the breadth of coverage. These differences critically impact research output assessments at the country and subject area levels, posing a challenge and an opportunity for the scientometrics community. The Dimensions database emerges as a robust new player, particularly with its comprehensive coverage across Social Sciences and Arts & Humanities, suggesting a potential shift in future research evaluation paradigms.