Presentation at the Workshop on Open Scientometric Data Infrastructures, Leiden University, Leiden, The Netherlands, March 1, 2019.

1. Open data sources in VOSviewer
Nees Jan van Eck and Ludo Waltman
Centre for Science and Technology Studies (CWTS), Leiden University
Workshop on Open Scientometric Data Infrastructures
Leiden University, Leiden, The Netherlands
March 1, 2019

2. VOSviewer
1

3. Development
3

4. Data sources supported by VOSviewer
4

5. 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)
5

6. Data access
6
Download

7. 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
7
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]

8. Demonstration
10

9. 11

10. 12

11. 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)
13

12. 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
14

13. Thank you for your attention!
15