Library acquisitions lore contains a cautionary tale of a patron in a
demand- driven environment who spent a huge
chunk of the library budget on ebooks about bananas. This story and
others like it have been used to perpetuate
the argument that demand- driven acquisition will result in collections
that don’t appeal to a broad audience or are
otherwise unbalanced. Our study presents quantitative data addressing
these hypotheses.
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Conclusions from the cautionary tale: Phrase in terms of the banana story
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* Read online - Can think of as in- library use
* Download – can be thought of as a checkout
* Combined these, but ignored all casual use – i. e. click in and click out never
counted;
Every use indicates true interest in the content: a click through saying I want to
continue to view, or a copy command or a print command
* The ability to eliminate casual usage ( ie browsing) from EBL use data
distinguishes it from all other e- resource use data that we’re aware of
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* Length of book ownership had significant effect on number of uses and users per
book
* For simplicity, it was incorporated in to the response variables ( i. e. uses per year,
and unique users per year)
* Books owned less than 6 months were ignored to avoid high use per year ratio due
to a few uses in a short period of time—
when the analysis was repeated with books owned at least 1 year – there was no
affect on the pattern or strength of the effects
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* In all subsequent slides user books from user selected collections are in blue, and
those from preselected collections are in green
* Overall Average number of uses per year in general quite high ≈ 6 per year
* Average number of post- purchase uses per year is significantly greater for user-selected
ebooks ( 2x as high)
* Even though the total number of books ( n) in the user selected set is greater, this
has no effect on the result—
these are PER BOOK averages, so each book in the user selected collection is used
an average of 8.6x per year, and
each book the preselected collection is used an average of 4.3x per year
* This result rejects the hypothesis rejects the hypothesis that users will select
ebooks will be used less than pre- selected ebooks
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* Pattern of greater use for user- selected books is consistent across all 5 libraries: 4
of 5 are significantly different based on non- overlapping 95% confidencec intervals
* degree of difference varies from 1.75x to 4.5x
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* This figure shows for the number of unique users per ebook per year for the overall
user selected and preselected collections
* The average user- selected ebook was used by a significantly greater number of
different users per year ( about 2x as many)
* These data allow us to result rejects the hypothesis that users select books that are
only of interest to themselves
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* Here we see that pattern of wider use of user- selected ebooks is also consistent
across the 5 libraries, with the same 4 libraries showing
significantly wider use
• The degree of this effect varies from 1.75x to 3.3 times more unique users per book
per year in user- selected collections
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* Print book collections are often assessed by the percentage of their books with 0
checkouts
* Here we report the percentage of books with zero use in discrete collections
formed under both acquisition models
* In every case more than 90% of the books had been used at least once, and in 4 out
of 5 libraries, fewer books went unused in the user driven collections
* On average there were about 6x as many unused books in the pre- selected
collections
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* At a broad disciplinary level, 4 of 5 libraries had similar subject profiles for the
collections built under the two acquisition models
* For the one library ( K) where the profiles appear to be different, the preselected
collection seemed to over- emphasize Sci& Tech books vs their user selected
collection
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At a slightly more granular level, subject profiles of the two types of collections
also appear to be similar
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Same data in tabular form with a few additional classes included
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