BMC Bioinformatics' delayed impact

Ronald Rousseau ronald.rousseau at KHBO.BE
Sat Nov 20 11:57:54 EST 2004

Dear Colleagues,

Matthew J. Cockerill’s editorial in BMC Bioinformatics [1] (brought to this
List’s attention by Eugene Garfield) is certainly to the point. Yet, I would
like to make some remarks.

The unofficial impact factor of BMC Bioinformatics as calculated by Cockerill
is slightly different from those with which it is compared. Indeed, all other
ones include journal self-citations while for BMC Bioinformatics, these
journal self-citations are not included. On the other hand, when adding BMC
Bioinformatics to the pool of source journals all other citation totals, and
hence, impact factors possible change (if these other journals are cited by
articles published by BMC Bioinformatics, and this, of course, within the time
window considered).

So, BMC Bioinformatics’ impact factor is indeed an estimate.

May I also stress the fact that this estimate is with respect to the ‘ISI
Universe’. There exist many journals, even important ones, outside this
universe, as BMC Bioinformatics’ editor knows very well. These journals are –
by definition - not considered in ISI’s  impact factor calculations.

Finally our colleague Johannes Stegmann is given credit for this estimation
method. Yet, to the best of my knowledge, Spaventi et al. [2] were the first
to propose this approach (in 1979). It was later re-invented by B.K. Sen et
al. [3]. Johannes Stegmann certainly deserves credit for bringing this method
to the attention of a wider audience [4], and, is, moreover, the person who
made the most fundamental studies of the constructed impact factors (see e.g.
[5]). Yet, BMC Bioinformatics’ editor joins the crowd, conveniently,
disregarding studies on impact factors published in information sciences

Ronald Rousseau
2004, November 20

[1]. Cockerill, M.J. (2004). Delayed impact: ISI’s  citation tracking choices
are keeping scientists in the dark. BMC Bioinformatics, 5:93.

[2]. Spaventi, J., Tudor-Silovic, N., Maricic, S. & Labus, M. (1979).
Bibliometric analysis of scientific journals from Yugoslavia. Informatologia
Yugoslavica, 11(3), 11-23.

[3]. Sen, B.K., Karanjai, A., & Munshi, U.M. (1989). A method for determining
the impact factor of a non-SCI journal. Journal of Documentation, 45(2), 139-

[4]. Stegmann, J. (1997). How to evaluate journal impact factors. Nature, 390,

[5]. Stegmann, J. (1999). Building a list of journals with constructed impact
factors. Journal of Documentation, 55(3), 310-324.

Ronald Rousseau
KHBO - Industrial Sciences and Technology
Zeedijk 101    B-8400  Oostende   Belgium
Guest Professor at the Library of the Chinese Academy of Sciences
Honorary Professor Henan Normal University (Xinxiang, China)
E-mail: ronald.rousseau at
web page:

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