Large-scale analysis of bibliometric
data sources
Nees Jan van Eck
Centre for Science and Technology Studies (CWTS), Leiden University
8th LCDS Meeting: Statistics & Data Science
Leiden, November 13, 2015
About myself
• Master in computer science
• PhD thesis on bibliometric
mapping of science
• Researcher at CWTS since 2009
• Research focus on analysis and
visualization of bibliometric
networks
1
Centre for Science and Technology
Studies (CWTS)
• Research center at Leiden University
focusing on science and technology
studies
• About 30 staff members
• History of more than 25 years in
bibliometric and scientometric
research
• Contract research
• Full access to large bibliographic
database (Web of Science and
Scopus)
2
Bibliographic databases: ‘Big data’
3
Web of Science Scopus
Journals 12,000 20,000
Publications 45 million 35 million
Citations 1 billion 0.9 billion
Bibliometric networks
4
Web of
Science
Scopus
Citation network
of publications
Co-authorship network
of authors / organizations
Co-citation network
of pubs / authors / journals
Co-occurrence network
of terms
Bibliographic coupling network
of pubs / authors / journals
Bibliographic
database
Outline
• Software tools
• Network analysis techniques
• Analysis of data science
5
Software tools
6
Software tools
• VOSviewer (www.vosviewer.com)
– Tool for constructing and visualizing bibliometric networks
• CitNetExplorer (www.citnetexplorer.nl)
– Tool for visualizing and analyzing citation networks of
publications
• Both tools have been developed together
with my colleague Ludo Waltman 7
VOSviewer
8
Map of university co-authorship
network
9
Map of journal citation network
10
CitNetExplorer
11
Network
analysis
techniques
13
Network analysis techniques
14
Layout:
• Visualization of similarities
(VOS)
Community detection:
• Weighted modularity
• Smart local moving algorithm
Smart local moving algorithm
15
Q = 0.4198
Q = 0.3791
Reduced
network
Local moving
heuristic in
subnetworks
Local moving heuristic
Original
network
Algorithmically constructed
classification system of science
• 16.2 million publications from the period 2000–
2014 indexed in Web of Science
• 241.7 million citation relations
• Classification system of 3 hierarchical levels:
– 28 broad disciplines
– 813 fields
– 3,822 subfields
16
17
Breakdown of scientific literature into
813 fields
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
Publications in scientometrics
subfield
18
Time-line map of highly cited
scientometrics publications
19
Analysis of
data science
20
What is data science?
• Empirical operationalization of data science based
on publications with ‘data’ in title or abstract
21
Wikipedia: “Data Science is an interdisciplinary field
about processes and systems to extract knowledge
or insights from data … which is a continuation of
some of the data analysis fields such as statistics,
data mining, and predictive analytics”
LCDS: “Data Science … deals with finding, analyzing
and validating complex patterns in data. Data
Science methods are indispensable for maintaining a
competitive edge in all disciplines in science”
Growth of data-driven research
22
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
20%
1990 1995 2000 2005 2010 2015
Percentageofpublications
% 'data' publications % 'theory' publications
23
Breakdown of scientific literature into
813 fields
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
24
Data-driven nature of different
scientific fields
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
% pub. with ‘data’ in title or abstract
25
Data-driven nature of different
scientific fields
artificial
intelligence
statistics
bioinformatics
neuroimaging
pattern
recognition astronomy
earth
water
weather
climate
remote
sensing
nutrition
obesity
addiction
% pub. with ‘data’ in title or abstract
Data science fields (at least 20% ‘data’
publications)
26
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
Term map of data science fields
27
28
Leiden University’s publication output
in data science fields
Social sciences
and humanities
Biomedical and
health sciences
Life and earth
sciences
Mathematics and
computer science
Physical
sciences and
engineering
Leiden University’s institutes with most
publications in data science fields
• Leiden Observatory
• LUMC
• Faculty of Archaeology
• Institute of Psychology (FSW)
• Centre for Science and Technology Studies (FSW)
• Mathematical Institute (Science)
• Institute of Biology Leiden (Science)
• Leiden Institute of Advanced Computer Science
(Science)
29
LUMC departments with most
publications in data science fields
• Medical Statistics and Bioinformatics
• Rheumatology
• Psychiatry
• Radiology
• Clinical Epidemiology
• Human Genetics
• Neurosurgery
• Cardiology
• Clinical Oncology
• Endocrinology 30
Term map based on Leiden University’s
publications in data science fields
31
Do it yourself!
32
www.vosviewer.com www.citnetexplorer.nl
Thank you for your attention!
33

Large-scale analysis of bibliometric data sources

  • 1.
    Large-scale analysis ofbibliometric data sources Nees Jan van Eck Centre for Science and Technology Studies (CWTS), Leiden University 8th LCDS Meeting: Statistics & Data Science Leiden, November 13, 2015
  • 2.
    About myself • Masterin computer science • PhD thesis on bibliometric mapping of science • Researcher at CWTS since 2009 • Research focus on analysis and visualization of bibliometric networks 1
  • 3.
    Centre for Scienceand Technology Studies (CWTS) • Research center at Leiden University focusing on science and technology studies • About 30 staff members • History of more than 25 years in bibliometric and scientometric research • Contract research • Full access to large bibliographic database (Web of Science and Scopus) 2
  • 4.
    Bibliographic databases: ‘Bigdata’ 3 Web of Science Scopus Journals 12,000 20,000 Publications 45 million 35 million Citations 1 billion 0.9 billion
  • 5.
    Bibliometric networks 4 Web of Science Scopus Citationnetwork of publications Co-authorship network of authors / organizations Co-citation network of pubs / authors / journals Co-occurrence network of terms Bibliographic coupling network of pubs / authors / journals Bibliographic database
  • 6.
    Outline • Software tools •Network analysis techniques • Analysis of data science 5
  • 7.
  • 8.
    Software tools • VOSviewer(www.vosviewer.com) – Tool for constructing and visualizing bibliometric networks • CitNetExplorer (www.citnetexplorer.nl) – Tool for visualizing and analyzing citation networks of publications • Both tools have been developed together with my colleague Ludo Waltman 7
  • 9.
  • 10.
    Map of universityco-authorship network 9
  • 11.
    Map of journalcitation network 10
  • 12.
  • 13.
  • 14.
    Network analysis techniques 14 Layout: •Visualization of similarities (VOS) Community detection: • Weighted modularity • Smart local moving algorithm
  • 15.
    Smart local movingalgorithm 15 Q = 0.4198 Q = 0.3791 Reduced network Local moving heuristic in subnetworks Local moving heuristic Original network
  • 16.
    Algorithmically constructed classification systemof science • 16.2 million publications from the period 2000– 2014 indexed in Web of Science • 241.7 million citation relations • Classification system of 3 hierarchical levels: – 28 broad disciplines – 813 fields – 3,822 subfields 16
  • 17.
    17 Breakdown of scientificliterature into 813 fields Social sciences and humanities Biomedical and health sciences Life and earth sciences Mathematics and computer science Physical sciences and engineering
  • 18.
  • 19.
    Time-line map ofhighly cited scientometrics publications 19
  • 20.
  • 21.
    What is datascience? • Empirical operationalization of data science based on publications with ‘data’ in title or abstract 21 Wikipedia: “Data Science is an interdisciplinary field about processes and systems to extract knowledge or insights from data … which is a continuation of some of the data analysis fields such as statistics, data mining, and predictive analytics” LCDS: “Data Science … deals with finding, analyzing and validating complex patterns in data. Data Science methods are indispensable for maintaining a competitive edge in all disciplines in science”
  • 22.
    Growth of data-drivenresearch 22 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20% 1990 1995 2000 2005 2010 2015 Percentageofpublications % 'data' publications % 'theory' publications
  • 23.
    23 Breakdown of scientificliterature into 813 fields Social sciences and humanities Biomedical and health sciences Life and earth sciences Mathematics and computer science Physical sciences and engineering
  • 24.
    24 Data-driven nature ofdifferent scientific fields Social sciences and humanities Biomedical and health sciences Life and earth sciences Mathematics and computer science Physical sciences and engineering % pub. with ‘data’ in title or abstract
  • 25.
    25 Data-driven nature ofdifferent scientific fields artificial intelligence statistics bioinformatics neuroimaging pattern recognition astronomy earth water weather climate remote sensing nutrition obesity addiction % pub. with ‘data’ in title or abstract
  • 26.
    Data science fields(at least 20% ‘data’ publications) 26 Social sciences and humanities Biomedical and health sciences Life and earth sciences Mathematics and computer science Physical sciences and engineering
  • 27.
    Term map ofdata science fields 27
  • 28.
    28 Leiden University’s publicationoutput in data science fields Social sciences and humanities Biomedical and health sciences Life and earth sciences Mathematics and computer science Physical sciences and engineering
  • 29.
    Leiden University’s instituteswith most publications in data science fields • Leiden Observatory • LUMC • Faculty of Archaeology • Institute of Psychology (FSW) • Centre for Science and Technology Studies (FSW) • Mathematical Institute (Science) • Institute of Biology Leiden (Science) • Leiden Institute of Advanced Computer Science (Science) 29
  • 30.
    LUMC departments withmost publications in data science fields • Medical Statistics and Bioinformatics • Rheumatology • Psychiatry • Radiology • Clinical Epidemiology • Human Genetics • Neurosurgery • Cardiology • Clinical Oncology • Endocrinology 30
  • 31.
    Term map basedon Leiden University’s publications in data science fields 31
  • 32.
  • 33.
    Thank you foryour attention! 33