1. Large-scale visualization of science
Nees Jan van Eck
Centre for Science and Technology Studies (CWTS), Leiden University
Data Science seminar
Faculty of Social and Behavioural Sciences, Leiden University, Leiden
December 7, 2018

2. Centre for Science and Technology Studies (CWTS)
• Strong emphasis on bibliometric and scientometric
research
• Research groups:
– Quantitative Science Studies
– Science and Evaluation Studies
– Science, Technology, and Innovation Studies
• Commissioned research for research institutions,
funders, governments, companies, etc.
1

3. CWTS Leiden Ranking
2

4. Bibliographic data sources
3
PATSTAT

5. Bibliographic data sources
4
Web of Science Scopus
Journals 20,000 24,000
Publications 55 million 45 million
Citations 1.2 billion 1.2 billion

6. Bibliometric networks
5
WoS
Scopus
Dimensions
PubMed
Crossref
Citation network
of pubs / journals / authors / orgs / countries
Co-authorship network
of authors / orgs / countries
Co-citation network
of pubs / journals / authors / orgs / countries
Co-occurrence network
of keywords / terms
Bibliographic coupling network
of pubs / journals / authors
Bibliographic
data source

7. Software tools and
techniques
6

8. VOSviewer
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9. Development
8

10. Users of VOSviewer
• Researchers
• Research institutions
• Research funders
• Scientific publishers
• Industry
9

11. Journal citation network based on Crossref data
10
https://www.cwts.nl/blog?article=n-r2r294&title=visualizing-freely-available-citation-data-using-vosviewer

12. CitNetExplorer
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13. Network analysis techniques
12
Layout:
• AKA mapping
• Visualization of similarities (VOS)
Clustering:
• AKA community detection
• Leiden algorithm

14. Leiden algorithm
13
Traag et al. (2018)

15. Algorithmic
classification systems
of science
14

16. CWTS publication-level classification system of
science
• Based on all articles in reviews in Web of Science between 2000 and 2017
• 21.2 million publications
• 374.1 million citation links
• Classification system of 3 hierarchical levels:
– 22 broad disciplines
– 868 fields
– 4,047 subfields
• Computational performance using the Leiden algorithm: less than 2hrs
15

17. 16
Structure of science based on 4,000 micro-level fields
Social sciences
and humanities
Biomedical and
health sciences Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
Size of a field is
proportional to the
number of publications in
the field

18. Publication output of FSW (2010-2016)
17
No. of FSW publications
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering

19. Publication output of FSW (2010-2016)
18
No. of FSW publications with
‘data’ in title or abstract
Scientometrics

20. Summary of scientometrics subfield
19
Cluster: 145
No. publications: 16,312
Top 5 terms No. pubs
bibliometric analysis 852
impact factor 495
h index 264
peer review 515
citation 642
Top 5 publications No. cits
hirsch, je (2005). an index to quantify an individual's scientific research output. p natl acad sci usa, 102(46), 16569-16572. 2,635
wuchty, s; et al. (2007). the increasing dominance of teams in production of knowledge. science, 316(5827), 1036-1039. 699
egghe, l (2006). theory and practise of the g-index. scientometrics, 69(1), 131-152. 609
king, da (2004). the scientific impact of nations. nature, 430(6997), 311-316. 496
newman, mej (2004). coauthorship networks and patterns of scientific collaboration. p natl acad sci usa, 101, 5200-5205. 488
Top 5 authors No. pubs Top 5 journals No. pubs
bornmann, l 221 scientometrics 2,865
thelwall, m 202 journal of informetrics 700
leydesdorff, l 175 journal of the american society for information science and technology 613
rousseau, r 161 plos one 339
egghe, l 133 research evaluation 324
Top 5 institutes No. pubs Top 5 departments No. pubs
univ granada 316 sch lib & informat sci (indiana univ) 106
kathol univ leuven 256 amsterdam sch commun res ascor (univ amsterdam) 97
leiden univ 249 ctr sci & technol studies (leiden univ) 90
indiana univ 246 sch publ policy (georgia inst technol - atlanta) 88
univ wolverhampton 216 trend res ctr (asia univ) 84
0
200
400
600
800
1,000
1,200
1,400
1,600
2000 2002 2004 2006 2008 2010 2012 2014 2016
No.publications

21. Publications in scientometrics field
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22. Term map of scientometrics field
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Peer review,
OA, careers,
and gender
Collaboration
Scientometric
indicators and
networks
Medical research
Country-level
analyses

23. 22
Time-line map of highly cited scientometrics
publications

24. Publication output of FSW (2010-2016)
23
No. of FSW publications with
‘data’ in title or abstract
Cognitive control
Psychometrics
Personality disorder
Childhood adversity,
adoption
Scientometrics

25. Thank you for your attention!
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26. Term map of cognitive control
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27. Term map of childhood adversity/adoption
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28. Term map of personality disorder
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29. Term map of psychometrics
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