The primary goal of this activity is to better understand the usage patterns of books in academic libraries: what books are (or are not) being used, how many copies are needed, the ideal size of subject collections, etc.

The study is limited to books and manuscripts since these materials typically circulate and circulation is a significant element in evaluating book collections.
Another goal is to investigate whether there has been a shift in the general patterns of use of library collections in a situation where libraries have instituted patron-initiated borrowing from one another.

This project uses OhioLINK circulation data and OCLC WorldCat bibliographic and holdings data to address these concerns. This is a rare and valuable combination, which has been leveraged through the working partnership between OhioLINK, the Collection Building Task Force, and OCLC Research.


Final Report

Analysis Results



Other outputs

  • The base data file of nearly 30 million circulation records for books held by OhioLINK libraries, enhanced with WorldCat bibliographic data, is publicly available under the Open Data Commons Attribution license (an open license) to download for study and research. This is the largest and most diverse set of academic usage data for books ever collected.
  • A repository of data about the circulation of monographs that can be correlated against such data points as subject, age of material, location and publisher is provided in a series of institution-specific spreadsheets summarizing the analysis.
  • Two participant workshops


Recent decades have seen the growth of library consortia that enable libraries to work collaboratively on building collections and sharing resources. In today's environment, who owns materials doesn’t matter as much as having the right materials available to meet user needs. The key lies in determining which materials are the "right" ones.

Collection analysis can provide information relative to this task, as well as a basis on which selectors can adjust their behavior to reflect collective, as well as local, conditions.

One historic problem for cooperative collection development is a lack of data to demonstrate to selectors how many copies of a given item were actually needed to meet circulation needs.
The distribution of copies also is an issue. Where are there too many copies? Where are more needed?  With 600,000 potential users, some duplication is important, so OhioLINK was careful to refer to their charge as reducing unnecessary duplication.

OhioLINK is a major library consortium that includes most academic libraries in the state of Ohio. Resource sharing, which is a primary function of the consortium, is supported by an infrastructure that includes a strong delivery system, a union catalog, a shared online system and an established history of cooperation. These characteristics make it an ideal focus for a study of this type.


Researchers expect that the analysis of circulation data will change acquisition behavior and that resource dollars can be allocated more effectively as a result. Such data may also be relevant to considerations of building cooperative collections at the regional level.


OhioLINK’s Collection Building Task Force (CBTF) identified the data needed, and worked closely with OCLC Research to plan the study. During the spring of 2007, and again a year later, the library systems managers at each of the OhioLINK libraries were asked to generate a file of circulation records for all their print books and manuscripts.
These records were matched to the corresponding bibliographic record in OCLC's WorldCat database. When possible, OhioLINK records lacking OCLC numbers were matched to WorldCat records using either the LCCN or the ISBN. All matches were validated by comparing the brief title in the circulation record with the title in the matching WorldCat record. The records included the annual circulation from the spring of 2007 to the spring of 2008.

Collectively, the OhioLINK libraries hold an extensive collection of non-English language books: a total of 2,383,462 items, almost nine percent of the collective collection.

A key part of the study is an analysis by subject. Each book was categorized into one of 647 subject areas based on the Library of Congress Classification in the corresponding WorldCat bibliographic record. The subject categories were then grouped into 9 broad subject areas.
Obsolescence, the decrease in demand over time, is widely assumed to be a major factor affecting circulation and has been extensively studied. The OhioLINK data provides a nearly ideal synchronous view to use to examine the influence of age on book usage. There is detailed information in the bibliographic record and the age of the material can be determined from the publication date. Since the corresponding circulation information is also available, obsolescence rates can be computed.

Duplication is an important and frequently discussed issue. A major concern regards how much duplication is necessary vs. how much is excessive. Every dollar spent on duplicating resources is a dollar less that is available to acquire unique materials. This study addresses this issue by examining duplication within OhioLINK libraries and how it has changed over time.


Most recent updates: Page content: 2014-10-29


Edward T. O'Neill

Team Members


OhioLINK Collections Building Task Force

  • Joyce Baker, Belmont Technical College
  • Margo Warner Curl, The College of Wooster
  • Danny Dotson, The Ohio State University
  • Celeste Feather, OhioLINK
  • Phil Flynn, Wright State University
  • Julia Gammon, University of Akron
  • Jessica Grim, Oberlin College
  • Rob Kairis, Kent State University, Stark Campus
  • Kevin R. Messner, Miami University
  • Andrew Whitis, Defiance College
  • Carol Zsulya, Cleveland State University

link to OhioLINK

OhioLINK Analysis Results:


This activity is a part of the Understanding the System-wide Library theme.