Tuesday, 17 June 2008

Impact Factors - The Basics

Impact Factors - The Basics - Part 1 (Cross 2008) is an explanatory guide to Impact Factors [IFs] from by Taylor & Francis. It does in fact cover the basics, what impact factors are and how they are calculated. However, it goes into greater detail on the very important topic of Subject Variation within Impact Factors including some very helpful graphs to illustrate the point. Here are some of the key figures made:

  • Average category impact factors for Economics, Nursing, Education & Educational Research and Business are all less then one. This compares with the top category of Cell Biology at c5.7

  • The coverage of journals in the Social Sciences by the Journals Citation Reports [JCR] are significantly less that the Sciences. For example Economics c 42% and Business and Management c33%. This compares with the top category Physics at c83%

  • The rates of citing in the Impact Factor Window (2 years) are higher in the Sciences, for example Cell Biology 22% compared with Economics at 8%

These figures provide a big health warning to comparing IFs even between apparently related subjects - there is also variation within subjects. The guide is just 7 pages long and worth a read especially for those researching in arts, humanities and social sciences who may wonder at the comparatively higher IFs of scientific colleagues.


Cross, J., 2008. Impact Factors - The Basics - Part 1. London: Taylor & Francis. Available from: http://www.tandf.co.uk/libsite/newsletter/issue9/Back_to_Basics.pdf [Accessed: 17 June 2008].


Journal Citation Reports [JCR] which publishes IF's is available here. It is ATHENS Authenticated.

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