OCLC Online Computer Library Center
Use of Circulation Statistics and Interlibrary
Loan Data in Collection Management
Lynn Silipigni Connaway, Ph.D.
Office of Research, Consulting Research Scientist
Heather Wicht
Electronic Resources Librarian
University of Colorado at Boulder Libraries
Jennifer Knievel
Humanities Reference and Instruction Librarian
University of Colorado at Boulder Libraries
Study Rationale
Statistics for decision making
– Remote storage
– Reduction of materials budget
– Collection management
• Selection
– Refinement of approval plan profiles
• Deselection
– WorldCat data mining
• Gap/overlap holdings analysis
• Unique/last copy
• Audience level
CU Boulder Libraries
University of Colorado (CU) at Boulder
– Research 1
– Doctoral granting
– 23,000 FTE
CU Libraries’ systems
– Innovative Interfaces Integrated Library System
– CLIO ILL Database
Methodology
Identification of a book
–
–
–
–
–
–
–
Monograph
Language material
No 007, except a, b, or d
No 245 $h
No 008, except d or r
Must have 260 $b or 020
300 $a must include >49 pages
Methodology
Scope
–
–
–
–
Books owned by CU Libraries, except Law Library
1/1/98-12/31/02
Text, including microform for ILL borrowing only
Exclusions
•
•
•
•
•
Foreign language
Government documents
Dissertations and theses
Manuscripts
Music
Methodology
Data sources CU
– ILL borrowing data from CLIO
• Eliminated canceled requests
– Circulation data from Innovative Circulation
Module
• Books circulated 1 or more times
• Number of circulations versus number of items
circulated
– Holdings data from OCLC WorldCat
Limitations
WorldCat holdings data
– Include non-circulating books
– Not complete holdings for CU library
Circulation, ILL, and holdings data
– Eliminated books with no LCC for NATC
subject analysis = 112,499 titles
Results
1,146,655 books (holdings)
343,869 items circulated
25,038 ILL borrowing requests for
books
North American Title Count (NATC)
• Conspectus Divisions
Results
Use factor
– Circulation within subject/holdings within
subject
Ratio of borrowings to holdings
– ILL within subject/holdings within subject
Results
Use Factor
– Low
• Library science, generalities, and reference
4,498/51,985=.09
• Physical education and recreation
2,505/25,996=.10
• Anthropology
3,935/29,126=.14
– High
• Engineering and technology
21,799/17,155=1.27
• Physical sciences
10,127/7,097=1.43
• Computer science
5,480/2,048=2.68
Results
Ratio of borrowing to holdings
– Low
• Anthropology
103/29,126=.004
• Library science, generalities, and reference
280/51,985=.005
• Political science
439/67,719=.006
– High
• Agriculture
644/13,812=.047
• Music
597/12,239=.049
• Engineering and technology
1,939/17,155=.113
Future Research
Circulation, ILL, and holdings data
– Publication date
– Publisher
– Publication date within NATC subjects
ILL data
– Status and department correlated to NATC
subjects
Number of items circulated
OCLC Online Computer Library Center
Questions and Discussion
connawal@oclc.org
Heather.Wicht@colorado.edu