From: Frederick Friend <[log in to unmask]>
Date: Thu, 19 Apr 2012 12:57:08 +0100

Ann has raised a very interesting topic which goes to the heart of how we
measure the value of libraries. It could be said that a library's value does
not lie in the number of uses of items in its collection, but unfortunately
descriptions of value without numbers attached to the descriptions do not
cut much ice with those providing the money to support libraries. And yet
arriving at reliable and comparable usage statistics is an impossible task,
for the reason Bryan Skib outlines, i.e. that so many variable factors enter
the calculation. Any number has to be accompanied by an explanation of the
factors used to calculate the number. Change one factor - such as the
percentage of older material - and the number becomes meaningless in talking
to policy-makers.

What can be valuable are year-on-year comparisons starting from a reliable
baseline, and used in a context which takes account of the profile of a
particular library. So for example, it would be possible to compare the
usage of digital items in a particular library over time, building in a
growth factor for the size of the collection. However, it would be very
unreliable to compare that statistic with a figure for the usage of paper
items over the same period, given the fundamentally different factors which
differentiate electronic usage from paper usage. A focused statistic could
help a library in making a case for support of the library for particular
resources, but the more general the statistic and the greater the attempt to
make comparisons between libraries, the more open to challenge any statistic
will be.

Good luck to all library statisticians!

Fred Friend
Honorary Director Scholarly Communication UCL

-----Original Message-----
From: "Skib, Bryan" <[log in to unmask]>
Date: Wed, 18 Apr 2012 16:30:40 +0000

What counts as use?

For reading, there would have to be leveling off unless campus
enrollments and staffing increase. How much can one person consume in
this manner? Expansion of access to alumni or the general public would
of course change the demographics. Further, the max number of uses
will be distributed across an ever larger body of materials, competing
for attention. The percent of older material that continues to see use
should be higher for digital than for print, given ease of access.
Will aggregate collection management and demand-driven acquisition
strategies reduce the portion of our collections that never see use?
Will restrictions on resource sharing reduce the external use of what
we choose to license?

If the question is about use of online reference works and A&I
services, users may well prefer other tools.

Higher portions of the content might see a different form of use to
the degree that large-scale full-text searching or textmining is
enabled.

My local picture strikes me as mixed, with continued (but slowing)
growth in use -- and yet I hesitate to jump to conclusions since
(overall) we are not always comparing apples to apples, or counting
the same things in the same way.

Bryan Skib
Associate University Librarian for Collections
818 Hatcher Library
University of Michigan