Google Scholar, Web of Science, and Scopus: a systematic comparison of citations in 252 subject categories
Open accessPreprint — published as 10.1016/j.joi.2018.09.002 · Paper page
Abstract
Despite citation counts from Google Scholar (GS), Web of Science (WoS), and Scopus being widely consulted by researchers and sometimes used in research evaluations, there is no recent or systematic evidence about the differences between them. In response, this paper investigates 2,448,055 citations to 2,299 English-language highly-cited documents from 252 GS subject categories published in 2006, comparing GS, the WoS Core Collection, and Scopus. GS consistently found the largest percentage of citations across all areas (93%-96%), far ahead of Scopus (35%-77%) and WoS (27%-73%). GS found nearly all the WoS (95%) and Scopus (92%) citations. Most citations found only by GS were from non-journal sources (48%-65%), including theses, books, conference papers, and unpublished materials. Many were non-English (19%-38%), and they tended to be much less cited than citing sources that were also in Scopus or WoS. Despite the many unique GS citing sources, Spearman correlations between citation counts in GS and WoS or Scopus are high (0.78-0.99). They are lower in the Humanities, and lower between GS and WoS than between GS and Scopus. The results suggest that in all areas GS citation data is essentially a superset of WoS and Scopus, with substantial extra coverage.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Larger, multidisciplinary search systems seem to provide more complete citation information than smaller specialized search systems.
“larger, multidisciplinary search systems seem to provide more complete citation information than smaller specialized search systems.”
Comparisons of citation indexes generally rate Google Scholar as the most comprehensive.
“Comparisons of citation indexes generally rate Google Scholar as the most comprehensive.71, 72, 73”
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cited by
Sorted by citations
Gusenbauer, M., & Haddaway, N. R. (2020) · Research Synthesis Methods · doi:10.1002/jrsm.1378 · Cited by 2,379 · see citing works
Gusenbauer, M. (2019) · Scientometrics · doi:10.1007/s11192-018-2958-5 · Cited by 687 · see citing works
A systematic comparison of deforestation drivers and policy effectiveness across the Amazon biome
Hänggli, A., Levy, S. A., Armenteras, D., Bovolo, C. I., Brandão, J., Rueda, X., & Garrett, R. D. (2023) · Environmental Research Letters · doi:10.1088/1748-9326/acd408 · Cited by 73 · see citing works
- Authors
- Martín-Martín, A., Orduna-Malea, E., Thelwall, M., & López-Cózar, E. D.
- Affiliations
- University of Wolverhampton (GB)
- Venue
- Journal of Informetrics
- Publisher
- Center for Open Science
- Published
- 2018-08-15
- Volume
- 12
- Issue
- 4
- Pages
- 1160-1177
- ISSN
- 1751-1577 (ISSN-L)
- OpenAlex
- W2886599162
- Cited by
- 1,990
- References
- 0
- Citations by year
- 2026: 278 · 2025: 325 · 2024: 288 · 2023: 277 · 2022: 279 · 2021: 285 · 2020: 174 · 2019: 78 · 2018: 5 · 2017: 1
- FWCI
- 103.52
- Type
- journal article
- Language
- en
- Open access
- green
- hdl.handle.net
- Licence
- cc-by-nc-nd
- Locations
- Journal of Informetrics (publishedVersion)
- Wolverhampton Intellectual Repository and E-Theses (University of Wolverhampton) (acceptedVersion, cc-by-nc-nd)
- arXiv (Cornell University) (submittedVersion)
- RePEc: Research Papers in Economics (submittedVersion)
- Institutional Repository of the University of Granada (University of Granada) (submittedVersion, cc-by-nc-nd)
- LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (submittedVersion, cc-by-nc-nd)
- RiuNet (Universitat Politècnica de València) (submittedVersion, cc-by-nc-nd)
- SocArXiv (OSF Preprints) (submittedVersion)
- OSF Preprints (OSF Preprints) (submittedVersion)
- arXiv (Cornell University)
- Funders
- Universidad de Granada
- Topics
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › scientometrics and bibliometrics research
- Physical Sciences › Computer Science › Information Systems › Web visibility and informetrics
- Physical Sciences › Computer Science › Information Systems › Library Science and Information
- Keywords
- Google Scholar, Web of Science, Scopus, citation counts, citation coverage, highly cited papers, research evaluation, bibliographic databases, subject categories
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
