Journal Impact Factors

The "impact factor" of a journal is a measure of the frequency which an average article in the journal is cited within a specified period of time. Obviously higher impact journals are "better" than lower impact journals in their visibility and their overall professional influence. The problem with this and similar measures is in the measurement. The data are produced by Thomson Reuters, an organization whose database includes only a small number of archaeology journals. So if most of our journals are not included in the calculations, how useful is this measure? Also, the calculations do not include citations in books and book chapters, which seriously disadvantages the humanities in comparison with the sciences. This largely explains why, within anthropology, physical anthropology journals have much higher impact scores than journals in cultural anthropology (with archaeology in between).  If you want to read more about impact factors, I'll put some citations below.

Anyway, what prompted this posting is an email I just received from Elsevier about how the impact factors of their archaeology journals are going up. I guess this is a good thing. I have long thought that archaeology journals have low impact factors (compared to journals in the sciences, for example). But look at the information below from Elsevier. Wow, archaeology trumps the history and philosophy of physics in journal impact measures! (Notice that Elsevier did NOT include any science journals for comparison).

Your should take these and other citation data with a grain of salt. If you want to read up on the topic, see the references below.

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Dear Michael E. Smith, The latest impact factors* for Elsevier's Arts and Humanities journals have just been released and highlights include... Journal Of Archaeological Science 2008 Impact Factor WAS 1.779 2009 Impact Factor NOW 1.847 Journal Of Anthropological Archaeology 2008 Impact Factor WAS 1.121 2009 Impact Factor NOW 1.667 Studies In History And Philosophy Of Modern Physics 2008 Impact Factor WAS 0.562 2009 Impact Factor NOW 0.783 Studies In History And Philosophy Of Science 2008 Impact Factor WAS 0.178 2009 Impact Factor NOW 0.424 Endeavour 0.154 0.16

Hicks, Diana
1999    The difficulty of achieving full coverage of international social science literature and the bibliometric consequences. Scientometrics 44:193-215.

Leydesdorff, Loet
2007    Caveats for the Use of Citation Indicators in Resesarch and Journal Evaluations. Journal of the American Society for Information Science and Technology 59:278-287.

Nederhof, Anton J.
2006    Bibliometric monitoring of research performance in the Social Sciences and the Humanities: A Review. Scientometrics 66:81-100.

Nehlo, L.I. and K. Yang
n.d.    A New Era in Citation and Bibliometric Analyses: Web of Science, Scopus, and Googld Scholar. Journal of the American Society for Information Science and Technology in press.