Impact factor is the scale that the commercial journals like to cite
because it measures how often their articles are cited (IF = number of
articles from a journal cited in the past two years/number of articles
published in that journal over the last 2 years). IF's are used for
many purposes by many different people: promotions,
advertising by the journal, enticements for authors, funding, library
purchases, deans seeking assurance, authors worried about the size of
their own impact, etc.
Of course, with the initiation of many electronic journals in
paleontology (PalaeoElectronica, Jour. Paleo, Paleobiology, all the
Elsevier journals, etc.) the audiences may be much larger. We can
measure hits on the journals, but I am unsure if anyone records domain
names or computers from which the hits originate. PE does this, if
I recall correctly. These would be alternatives to IFs since it
might indicate numbers of interested people (or maybe readers?).
IFs indicate contributions to the field in a more substantial way than
just reading a paper, or at least they are supposed to.
I doubt it.
IF probably means little for paleontology in general however because our
field is divided in what might be called theoretical and archival
parts. Systematics, biostrat, biotic descriptions, etc, may
not be immediately used, as these are fairly specialized, hence journals
with lots of this (JP and most other standard paleo journals) don't have
high IFs. In the theory section, certain papers will get well cited
because they are dealing with currently hot topics. Paleobiology,
for example, does very well. Others with big followings, like
Paleoceanography, also get high IFs. On-line journals seem to
be picking up somewhat as people discover that it is very easy to do a
keyword search, find articles easily, and cite them, sometimes without
even reading them just so the author looks like he/she knows the very
latest stuff.
Whenever you see IFs cited, think carefully about why that is
happening. Commercial journals are quick to note their high IFs
(not so quick to talk about the low IFs). Then think carefully
about what that means. A low IF might mean a special issue
dealing with a small topic (sponges) was issued that year, or that the
field requires time to respond to papers (i.e., biostrat where
correlations and comparisons take a lot of time, longer than the 2-year
inclusion period), or for high IFs, that a lot of people work in a field
or that only one journal accommodates most of the papers.
Sometimes these things, including numbers of citations to an individual's
papers, are used for promotions. None of these should ever be used
without careful analyses. Some of the most cited papers were
actually very bad ones, and people took lots of shots at the
author. For promotions, I'd imagine you'd only want to include
citations that thought your paper was good!
Be careful with these various numbers. ISI has an old but very
useful guide to their IF numbers at
http://www.isinet.com/cgi-bin/htm_hl?DB=ISIsite&STEMMER=en&WORDS=impact+factor+&COLOUR=Purple&STYLE=s&URL=http://sunweb.isinet.com/isi/hot/essays/journalcitationreports/7.html#muscat_highlighter_first_match
. If you search in BIOSIS for Impact factor you will get over 50 hits, some of which deal with other issues but a large number of them trying to get at what these journal IFs mean. Interesting reading, actually.
Subscribers to journals are usually divided into individuals (members) and institutional (libaries). Since library copies may be used by many more people (even more now that a lot of them are on-line through libraries), we have little way to know how many people actually use our journals. Some libraries keep track of how many times they have to re-shelve books, as a way of counting users, but this has big error factors, such as readers who use the journal and put it back or users who take them from the shelf just to increase the apparent use to preserve the subscriptions, etc.
JHL
At 03:01 PM 11/12/2004, you wrote:
On Fri, 12 Nov 2004, brcgranier wrote:
> Date: Fri, 12 Nov 2004 23:27:11 +0100
> From: brcgranier <brcgranier@wanadoo.fr>
> Reply-To: paleonet@nhm.ac.uk
> To: paleonet@nhm.ac.uk
> Subject: paleonet How is measured the impact of a journal or a paper?
>
> I have heard about the impact factor but I don't really know what is behind!
I suggest:
http://www.isinet.com
>
> Another question concerns the visibility of paleontological journals: in my opinion, it should be measured it in terms of number of printed copies or number of subscribers (libraries + individuals). Do you have any idea about the number of subscribers to the main paleontological journals, either national or international?
There are many improvables. Right now we have no other system.
>
> BG
>
Best regards,
Peter
**********************************************************************
Dr. Peter P. Smolka
University Muenster
Geological Institute
Corrensstr. 24
D-48149 Muenster
Tel.: +49/251/833-3989 +49/2533/4401
Fax: +49/251/833-3989 +49/2533/4401
E-Mail: smolka@uni-muenster.de
E-Mail: PSmolka@T-Online.de
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