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Citation Databases

What they are and how to use them

Bibliometrics Overview

Welcome to Purdue University's Citation Databases Research Guide

Here you will find...

  1. Information on citation databases
  2. Descriptions of these databases
  3. Helpful examples on how to use them
  4. Use cases for each of the major citation databases
  5. Useful tips and tricks on how to best make use of them


Here are some definitions of common terms made use of by citation databases

  • Bibliometrics is the statistical analysis of scholarly output like articles, book chapters, and reviews.
  • Altmetrics: is the statistical analysis of alternative forms of capture such as twitter impressions of a piece of scholarly output.

Some common metrics are the H-index, Journal Impact Factor, and the FWCI (called CNCI in Web of Science).

  • H-Index is a measure of how many times a journals published articles are cited, an index of fifteen means an article has been cited 15 times.
  • Journal Impact Factor (IF) – A measurement of how many times a journal’s published articles are cited by different researchers.
  • FWCI – Publication Field weighted citation indices indicate how the number of citations received by researcher’s publications compared to the average number for similar publications.
  • Category Normalized Citation Impact (CNCI) – Calculated using Web of Science, CNCI is “an indicator of impact normalized for subject focus, age and document type. A CNCI of 1 is at par with the world average, anything above 2 is twice the global average
  • SJR - Scimago Journal Rank is a measure of the "prestige" of journals which makes use of both the number of citations a journal accrues and the perception of those journals in the wider academic community
  • SNIP - Source Normalized Impact per Paper is a metric which accounts for the field specific differences between journals. The need for this is that some fields have different publishing practices, time frames, and constraints. This results in the need for a metric like SNIP which is calculated by comparing the citations per journal with the citation potential of the field as a whole, in other words it would measure of history journal against other history journals and vice versa for other academic disciplines


Here are the five most common Citation Databases' Key Strengths and Use Cases

Database Strengths Key Uses 
Scopus Particularly strong in social and hard sciences, coverage since 1970 Studying a researcher's impact over a long period of time, discovering research trends, and interdisciplinary research

Web of Science

Exceptionally strong hard sciences indexing, coverage since 1945 Author level metrics, discovering research trends, and production of literature reviews
Google Scholar Covers all disciplines, massive indexing capabilities, unknown coverage years Excellent for accessing and discovery of scholarly literature, spectacular coverage of non-English and international scholarly material. Note: given that it is a search engine it does not provide as many author level metrics as its competitors such as Scopus and Web of Science.
Dimensions Covers all disciplines, includes patents, and unknown coverage years (1.8 million citations) Discovery of patent information, 1.8 million citations available, and a free version make this a useful tool
PubMed Focuses on medical and hard sciences citations, coverage begins selectively in 1809 and comprehensibly in 1966 Production of medical and hard sciences literature reviews, literature discovery, and citation analysis. Note: given its special focus, not recommended for non-STEM research