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Research Impact: Citation Index Databases and Metrics


Citation metrics have been commonly used for recruitment, promotion and tenure (P &T) exercise, grand application, etc. In NTU, there are three citation index databases are used commonly to evaluate researchers’ impact: Web of Science, Scopus and Google Scholar.

Below are some essential features for these three citation databases (data accurate as of June 2018)

Citation Databases

Below are some essential features for these three citation databases (data accurate as of June 2018)
Web of Science Scopus Google Scholar
> 32,800 journals + books, proceedings, patents, and data sets > 22,800 serials titles,
> 150,000 books
Peer-reviewed papers, theses, preprints, abstracts, and technical reports
From 1900 - From 1970 - Not stated
Worldwide North American Bias Worldwide 50% from Europe, Latin America and Asia-Pacific Not stated
English Language Bias English Language Bias Multiple Languages
Strongest Coverage - natural sciences & engineering, computer science, materials sciences, patents, data sets Strongest Coverage - Life sciences, social sciences (including arts and humanities), physical sciences and health sciences Multidisciplinary

Main metrics used by these citation databases:
Web of Science Scopus Google Scholar
✔ h-index
✔ total publications
✔ sum of times cited
✔ sum of times cited
    (without self-citations)
✔ average citations per item
✔ times cited
✔ cited references
✔ h-index
✔ cited documents from
    [author’s name]
✔ documents by author
✔ total citations
✔ cited by (exclude self citations of
    selected author)
✔ h-index
✔ i10-index (number of publications
    with at least 10 citations)
✔ citations
✔ cited by

Some screenshots of main metrics taken from these citation databases: