Impact Factors

Definition

  • Impact factors are calculated by Thomson Scientific, the producer of the Web of Science citation index.
  • The impact factor of Journal A = number of citations to articles in Journal A in Web of Science in previous two years, divided by number of original research articles and reviews published by Journal A in the previous two years.

Where To Find Impact Factors and Journal Rankings

  • Thompson Scientific publishes current impact factors in the Journal Citation Reports( JCR ).
  • JCR includes impact factors for individual journal titles and lists of highly ranked journals by subject.
  • The JCR print volumes are available at the Reference Desk in Ellis Library along with some detailed supplementary material on microfiche.
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    • Journal Citation Reports Science Edition
      Ellis Library Ready Reference Z7403 .S32
    • Journal Citation Reports Social Science Edition
      Ellis Library Ready Reference Z7163 .S62
  • JCR volumes covering journal rankings for the previous year are usually published in late summer
  • There is not a humanities edition of the JCR.
  • Not all science and social science journals are included in the Journal Citation Reports

Further Information on Impact Factors