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RE: COUNTER posting from Peter Shepherd

I disagree with Peter's conclusion that:" There are many reasons
why PDF/html ratios may vary from publisher to publisher (archive formats; 
different practices in different subject fields,
to name but two) and not too much should be read into them."

My experience is that faculty and researchers citing articles
generally need pdf. I don't believe html is a substitute when it
comes time to cite an article in formal publication. This
experience suggests to me we should anticipate differences in
usage patterns are meaningful.

Chuck Hamaker
Associate University Librarian Collections and Technical Services
Atkins Library
University of North Carolina Charlotte
Charlotte, NC 28223

---------- Forwarded message ----------

I write in response to Phil Davis's recent comments on the
comparablity of the online usage statistics from different
COUNTER-compliant vendors. While I agree with Phil that COUNTER
is no panacea, I am confident that the COUNTER compliant usage
statistics from different vendors are much more comparable than
he believes. The results of the 2005 study that he reports are
interesting, but two siginificant developments have taken place
since it was published that render some of its conclusions rather
questionable. These developments are:

1. In 2005 only one COUNTER-compliant vendor required users to
download the full-text html version of an article before
accessing the full-text PDF. This vendor has since changed its
interface so that this is no longer a requirement and the user
can go straight to the PDF. While it is not COUNTER's job to
instruct vendors on the design of their user interfaces, we do
specify in the Code of Practice that it is not best practice for
vendors to require users to download html first.

2. In 2005 and 2006 we carried out a research project (sponsored
by JISC) which investigated ways of mitigating possible
'interface' effects' on COUNTER usage data. The results of this
project are reported in full on the JISC website at


These results tend to call into question the wisdom of drawing
too may conclusions about usage data based on the poportion of
PDF/html ful text downloads observed for different publishers. I
think that the following results are particularly noteworthy:

a) When a unique article filter is applied to the usage
statistics contained in Journal Report 1 ( Number of successful
full text article requests - in all formats), which reduces the
count to the number of unique article requests per session, the
reduction in the count is not particularly dramatic. Only in a
minority of cases do users download an article in more than one
format in a single session and it seems reasonable to assume
that in these cases users may actually want to use an article in
more than one format. ( Further studies into the use of different
article formats by users would shed more light on this).

2. There does not apear to be any relationship between the
reduction in the count produced by the application of the unique
article filter and the proportion of PDF/html downloads. The
publisher with a PDF/html ratio of 0.64 sees a similar reduction
in count, when the unique article filter is applied, to the
publisher with a PDF/html ratio of 7.69. These results indicate
that it would be ill-advised to draw any conclusions about
'inflation' of usage statistics from PDF/html download ratios.

While we continue with the work to further improve the COUNTER
usage statistics, we stand by the statements we have made in our
recent message. COUNTER has made usage statistics from different
vendors more comparable. The COUNTER statistics are not perfect,
but we feel that they are comparable enough for the purposes of
most librarians.

We must, of course, be alive to the dangers of
over-simplification, but the siren voices of over-interpretation
are equally tempting and just as hazardous; their call can,
indeed, be irresistible when so much data is so readily
available. There are many reasons why PDF/html ratios may vary
from publisher to publisher ( archive formats; different
practices in different subject fields, to name but two) and not
too much should be read into them.

Peter Shepherd, PhD


>>>At 05:46 PM 5/16/2007, Gillingham Emily wrote:
>>>Since the launch of the first COUNTER Code of Practice in 2002,
>>>libraries around the world have been able to compare and contrast
>>>the usage for different journals and databases across different
>>>subjects from different publishers.
>>As a former member of the Executive Board of Project COUNTER, and
>>as a former science librarian, I only have great respect and
>>admiration for this organization, its leadership, and its dedicated
>>board members.=A0=A0Yet the standardization of downloads and reports
>>has not resulted in panacea whereby librarians can simply compare
>>usage across different publishers. In a study of six
>>COUNTER-compliant publishers [see below], we report very large
>>differences in download patterns across publisher interfaces --
>>even controlling for identical journal content. As a result, there
>>needs to be more work on this front before librarians are persuaded
>>that they can simply compare the usage of journals and databases
>>across publisher platforms.=A0=A0At the least, Project COUNTER should
>>be cautious in making over-simplified statements that can result in
>>erroneous beliefs by those who are responsible for making sound
>>collection decisions.=A0=A0At worse, publishers may exploit this myth
>>to artificially inflate and manipulate the numbers they report.
>>eJournal interface can influence usage statistics: implications for
>>libraries, publishers, and Project COUNTER.
>>Philip M. Davis and Jason S. Price
>>JASIST (2006, vol 57, issue 9, p.1243-1248).
>>copy available: http://www.people.cornell.edu/pages/pmd8/
>>The design of a publisher's electronic interface can have a
>>measurable effect on electronic journal usage statistics. A study
>>of journal usage from six COUNTER-compliant publishers at
>>thirty-two research institutions in the United States, the United
>>Kingdom and Sweden indicates that the ratio of PDF to HTML views is
>>not consistent across publisher interfaces, even after controlling
>>for differences in publisher content.=A0=A0The number of fulltext
>>downloads may be artificially inflated when publishers require
>>users to view HTML versions before accessing PDF versions or when
>>linking mechanisms, such as CrossRef, direct users to the full
>>text, rather than the abstract, of each article. These results
>>suggest that usage reports from COUNTER-compliant publishers are
>>not directly comparable in their current form. One solution may be
>>to modify publisher numbers with 'adjustment factors' deemed to be
>>representative of the benefit or disadvantage due to its interface.
>>Standardization of some interface and linking protocols may
>>obviate these differences and allow for more accurate
>>cross-publisher comparisons.
>>Philip M. Davis
>>PhD Student (and former Science Librarian)
>>Department of Communication
>>Cornell University
>>email: pmd8@cornell.edu
>>work phone: 607 255-0354
>>web: http://www.people.cornell.edu/pages/pmd8/