Revision of Impact Factors

Pedro Pedro
Tue Sep 19 07:39:58 EDT 2000

"All of which, of course, leads to
the broader issue of a lack of some sort of standardized bibliometric measures
in general..."

This is true. The Impact Factor should be conceptualzed in a theoretical
framework where measure makes sense. An instrument for measurement it is


"The Rasch Model. Measuring The Impact of Scientific Journals: Analitical
Chemistry". JASIS 47(6):458-467, 1996.

"The Diffusion of Scientific Journals Analyzed through Citations". JASIS
48(10):953-958, 1997.

"Equating Research Production in Different Scientific fields" Information
Processing & Management Vol. 34, No 4, pp. 465-470, 1998.

are instances.

Pedro Alvarez
School of Economics
University of Extremadura.

At 10:51 18/09/00 -0400, you wrote:
>Excellent response! I amend my previous comments to apply only to the
>discussion of author self-citations in the context of efforts to measure or
>evalutate research performance or productivity.
>As an aside, I wonder if we as bibliometricians, in our rush to change the
>two-year citation window used by ISI to calculate the Impact Factor, have
>given due consideration to the potential lost of comparability? For all its
>faults, real and imagined, at least the ISI Impact Factor as currently
>calculated  provides some sort of standard that allows comparability between
>the results of various studies. The more special cases, ad hoc adjustments,
>and other  individualized tinkering that is done to the Impact Factor's
>calculation, the less comparable the end results are. This is particularly a
>problem when one is using citation anlysis as part of a larger study examining
>research performance and productivity, which to have meaningful results,
>involves some kind of comparative measures. All of which, of course, leads to
>the broader issue of a lack of some sort of standardized bibliometric measures
>in general...
>Eric Ackermann
>School of Information Sciences
>University of Tennessee-Knoxville
>eackerma at
>>> Date:    Fri, 15 Sep 2000 13:39:25 -0400
>>> From:    eackerma <eackerma at UTKUX.UTCC.UTK.EDU>
>>> Subject: Revision of Impact Factors
>>> While I find the current discussion of ISI's Impact Factor quite
>>> interesting,
>>> I'm afraid that I will have to take issue with the (apparently)
>>> widely
>>> accepted notion that all self-citations should be omitted from any
>>> impact considerations........................
>>> Therefore, until there are published studies in the literature that
>>> empirically demonstrate the necessity for doing so, removing all
>>> self-citations from the record before conducting a bibliometric
>>> evaluation of
>>> research performance seems to be an unnecessary activity. It only
>>> seems to add
>>> more work to the task of citation analysis for no good reason,
>>> while unfairly
>>> penalizing researchers in newer, highly specialized, or currently
>>> unpopular
>>> fields.
>>> Eric Ackermann
>>> School of Information Sciences
>>> University of Tennessee-Knoxville
>>> eackerma at
>>> ------------------------------
>>In response to the beginning and the end of Eric Ackerman's message,
>>I would comment as follows.
>>The selfcitations are of two kinds. (i) When authors cite their own
>>published work, irrespective of the source journals, and (ii) when
>>there are citations to the same journal in articles published in it.
>>Let me call (i) "authors selfcitations", and (ii) "journal
>>(i) In case of authors selfcitations one must certainly allow for
>>autors' necessity to "keep track" of her/his earlier publications.
>>But certainly there must be a limit to it. (Incidentally - is there
>>any analysis about the context type of authors selfcitations?) As far
>>as something in one's last paper has to be backed by explanations
>>already given in earlir publications - the authors selfcitations are
>>clearly indispensible.
>>However, once decided to use citation counting to  e v a l u a t e
>>individual   s c i e n t i f i c  input to the world knowledge, the
>>aim is to find out to what extent that individual's work has been
>>referred to by his/her PEERS in THEIR publications. (Some like to
>>name this "impact", I don't.) Obviously, the authors selfcitations
>>should be excluded for evaluative purposes.
>>(ii) Journal selfcitations are of interest in journals  e v a l u a t
>>i o n   (studies), a topic of particular importance to which I shall
>>come in another comment.
>>Suffice here to say that while journal selfcitations should NOT be
>>excluded, such data, recorded specifically as kind of a
>>"claustrophobic" index, ought to be analysed in comparing journals,
>>bearing in mind, of course, that there are new or exotic fields of
>>research with a very limited number of source journals.
>>Yours in discourse,
>>Do You Yahoo!?
>>Yahoo! Mail - Free email you can access from anywhere!
>>End of SIGMETRICS Digest - 15 Sep 2000 to 17 Sep 2000 (#2000-132)
Pedro Álvarez
Departamento de Economia Aplicada y Organizacion de Empresas
Facultad de Ciencias Economicas y Empresariales
Universidad de Extremadura
Avda de Elvas s/n                  06071-BADAJOZ      SPAIN
Tlfno Fax 924-289556      E-mail:palvarez at

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