Should we ditch impact factors?

doi:10.1136/bmj.39146.545752.BE

BMJ 2007;334:569 (17 March), doi:10.1136/bmj.39146.545752.BE

Feature

Should we ditch impact factors?

Richard Hobbs, head of primary care

Department of Primary Care and General Practice, University of Birmingham, Birmingham B15 2TT

f.d.r.hobbs@bham.ac.uk

Even advocates of impact factors admit that they are a flawedmeasure of quality. Gareth Williams believes we should get ridof them whereas Richard Hobbs thinks refinement is the answer

The first 150 words of the full text of this article appear below.

From 2008, state funding for academic research in the UK willbe calculated differently. The research assessment exercise,which is based substantially on (high intensity, high cost)peer review, will transfer to bibliometric scoring.¹ Such metricsinclude journal impact factors, published annually in JournalCitation Reports. The impact factor is based on the averagenumber of citations of individual "source" articles (originalpapers, research reports, and reviews) published in that journalduring the preceding two years.

Of course, as with most routinely collected data, there areproblems. Some of them are basic—only 2.5% of journalsare tracked² and not all disciplines routinely cite others'work. Numerous other non-quality factors drive article citationsand therefore the impact: reviews cite other articles the most³;basic sciences routinely cite many more references than clinicalsciences; short turnover science (principally basic) is widelyreferenced for a short time (enhancing scores in the . . . [Full text of this article]