Research Guides: Bibliometrics and Altmetrics: Measuring the Impact of Knowledge: Overview of Different Metrics

Overview of Different Metrics

	Web of Science	Scopus	Google Scholar
Subject Focus	Science Citation Index Social Science Citation Index Arts & Humanities Citation Index	Health Sciences Physical Sciences Social Sciences Life Sciences	Theoretically, all disciplines
Coverage	Over 12,000 peer-reviewed journals Over 1,300 open access journals 30,000 books with 10,000 added annually Over 2.6 M chemical compounds and 1 M chemical reactions 148,000 conference titles with 12,000 added annually	Over 21,500 peer-reviewed journals Over 360 trade publications Over 4,200 open access journals Over 120,000 book titles Over 7.2 M conference papers Over 27 M patent records	Books from Google Books Dissertations Peer-reviewed articles Patents Case law Trade journals Slide presentations Gray literature Newsletters Syllabi (if cited by scholarly articles)
Time Span	Some journals from 1900	Some journals from the 1820s	Some citations as far back as the 1660s and 1670s
Updated	Weekly	Daily	Unknown but generally quick
Strengths	Excellent search limits by discipline The most well-known and most used resource for citation analysis Citation analysis goes back farther than Scopus	Better open access journal coverage Better foreign language coverage Better Social Sciences & Arts/Humanities coverage	Excellent resource for finding cited references It's free May find more obscure references
Weaknesses	Weaker Arts/Humanities & Social Sciences content than Scopus	Cannot search by date any earlier than 1960	Too much irrelevant content in search results Few options for sorting results

Source: Citation Analysis Guide from University of Michigan. Authors: Paul Grochowski, Barbara Shipman, Deirdre Spencer, Sue Wortman.