Metrics: journal's impact factor skewed by a single paper


We have discovered a striking example of how the use of impact factors to judge journal performance can bias the whole evaluation system (Nature 465, 845; 2010, Nature 465, 864–866; 2010, Nature 465, 870–872; 2010).

A surprise in the 'all journals' category of Thomson Reuters' impact factors for 2009 is the meteoric rise to second position of the journal Acta Crystallographica A. That journal's impact factor, which has not exceeded 2.38 in the past four years, has hit a whopping 49.93. Such startling fluctuations are rare — compare, for example, the impact factors of Nature and the New England Journal of Medicine over the same period at 26.68–34.48 and 44.01–52.58, respectively.

Acta Crystallographica A had 5,966 citations in 2009 for 72 articles published in 2008, of which all — except one — received no more than three citations (data from ISI Web of Knowledge v. 4.98). However, a paper by G. M. Sheldrick entitled 'A short history of SHELX' (Acta Crystallogr. A 64, 112–122; 2008) clocked 5,624 citations. It seems that this article could be responsible for the sudden dramatic inflation of the journal's impact factor.

Author information



Additional information

See also Metrics: don't dismiss journals with a low impact factor .

See also Metrics: include refereeing as part of performance rating.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Dimitrov, J., Kaveri, S. & Bayry, J. Metrics: journal's impact factor skewed by a single paper. Nature 466, 179 (2010).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing