1. Open data sources in VOSviewer
Nees Jan van Eck
Centre for Science and Technology Studies (CWTS), Leiden University
Center of Scientometrics (CoS), National Science Library, Chinese Academy of Sciences
Beijing, China, April 12, 2019

2. VOSviewer
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3. Users of VOSviewer
• Researchers
• Research institutions
• Research funders
• Scientific publishers
• Industry
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4. Development
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5. Data sources supported by VOSviewer
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6. Bibliometric networks in VOSviewer
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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. Types of networks supported by each data source
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Co-authorship Co-
occurrence
Citation Bibliographic
coupling
Co-citation
Web of Science     
Scopus     
Dimensions     
PubMed     
Crossref     
Europe PMC     
Semantic Scholar     
OCC / COCI     
Wikidata     

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10. Limitations of data sources
• Web of Science (closed)
• Scopus (closed)
• Dimensions (closed, but open for research)
• Crossref (open, except for half of the citation data)
• OCC (open, but low coverage)
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11. Data access
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Download

12. API support for open data sources
• DOI files
• Interactive querying
– Supported by APIs of Crossref and Europe PMC
– Crossref API has restrictions in the type of queries that can be performed
– Europe PMC API is most flexible, but querying and retrieving citation data cannot be done using a
single API call
– Not supported by the APIs of Semantic Scholar, OCC, COCI, and Wikidata
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http://api.crossref.org/works?filter=issn:1751-1577,from-pub-date:2010-01-01
https://www.ebi.ac.uk/europepmc/webservices/rest/search?query=(TITLE:"zika" OR
ABSTRACT:"zika") AND PUB_YEAR:[2018 TO 2019]

13. Interactive querying
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16. Wish list for improving open data sources
• Expanding coverage of publications (OCC)
• Opening citations (Crossref)
• Opening other metadata, e.g. abstracts (Dimensions, Crossref, OCC)
• Improving completeness and standardization of metadata (Crossref)
• Improve APIs
– Add or expand interactive querying (Crossref, Europe PMC, OCC)
– Speeding up (OCC)
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17. Outlook
• Work together with data providers to improve their APIs
• Expand API support
• Add support for additional data sources
– Microsoft Academic
– OpenAIRE
– Lens.org
• Add support for full-text data sources
• Development of web-based version of VOSviewer
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18. Sneak preview
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19. Thank you for your attention!
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