[This message has been cross posted to slapam-l and lis-e-journals]
Dear Colleagues,
Apologies for cross posting. I am looking for statistics on the
chronological distribution of journal usage (or any article
repositories) in any given year, i.e. of all accesses in 2001, what
percentage goes to articles from 2001 - n, n = 0,1,2,... what is the
half-life, i.e. the number of publication years from the current year
which account for 50% of the current years total usage, or other
percentiles related to the depth of the back files available. I guess
that the distribution will be a superposition of at least two
distributions, one short-term, driven by journal browsing, and another,
more long-term driven by citations and the general aging patterns fo the
scientific literature. It would also be interesting to compare such data
to cited half lifes from ISI's Journal Citation Reports.
My immediate practical interest is to obtain a feeling and useful
estimates for the effect of making available back files of various
depths on usage (e.g., to take an extreme, the one year rolling file of
ScienceDirect Web Editions, vs. the standard 5 year-archive of
ScienceDirect). I realize that such characteristics will depend heavily
on the subject category (e.g., Computer Sciences vs. Chemistry vs.
Mathematics).
If you know of any literature on this subject or investigations on
e-journals usage statistics which have substantial data on this aspect
of journal usage (possibly JSTOR, the arxive?), whether published or
unpublished, I would appreciate if you could direct me to those sources,
or provide a short summary of the results if it is unpublished. (I
already know of Kevin Guthrie's presentation on JSTOR during the PEAK
conference 2000.)
Also, I am interested in learning about publishers who provide such time
profiling of usage statistics (at the moment, I am aware of only one,
the Royal Society of Chemistry. I will try to provide a summary for the
list of all correspondence that goes directly to me but of course you
may also reply via the list. Thanks for any advice!
Bernd-Christoph Kämper, Stuttgart University Library
--
Bernd-Christoph Kaemper, Dipl.-Physiker, Bibl.-Rat
Fachreferent für Physik und Koordination elektronischer Ressourcen
Universitätsbibliothek Stuttgart, Postfach 104941, 70043 Stuttgart
Tel +49 711 685-4780, Fax +49 711 685-3502, [log in to unmask]
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