Use of Circulation Statistics and Interlibrary Loan Data in Collection Management

1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. Results • 1,146,655 books (holdings) • 343,869 items circulated • 25,038 ILL borrowing requests for books • North American Title Count (NATC) • Conspectus Divisions

9. Results • Use factor • Circulation within subject/holdings within subject • Ratio of borrowings to holdings • ILL within subject/holdings within subject

10. 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

11. 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

12. 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

13. Questions and Discussionconnawal@oclc.orgHeather.Wicht@colorado.edu