Collection Analysis with Circulation, ILL and Collection Statistics: A Follow-up Presentation

1. Collection Analysis with Circulation, ILL and Collection Statistics: A Follow-up Presentation Lynn Silipigni Connaway OCLC, Inc. Heather Wicht University of Colorado Jennifer Knievel University of Colorado

2. University of Colorado at Boulder (CU-Boulder) • Research I, Doctoral granting institution • 26,500 FTE • Libraries hold ~3 million volumes (6/30/03) • 87,000 ILL requests in 2003 • 60,000 Lending Requests • 27,000 Borrowing Requests

3. Project Origins • Remote storage project at CU-Boulder • Collaboration with OCLC – mining WorldCat • Collection development study by John N. Ochola, Baylor University • Planning of pilot project • Identify data to be analyzed, collected in future • Assess usefulness of data to bibliographers • Declining monographic budget • Possible justification for maintaining or increasing monographic budget • Accountability for spending

4. Purpose of Study • Compare subject distribution • CU-Boulder holdings • ILL borrowing requests • Circulation

5. Local Systems • Software • Innovative Interfaces • CLIO Database • Data Gathering Methods • Innovative: Create Lists • CLIO: Microsoft Access Queries

6. Project Scope • Books only • Law library excluded • Gov Docs excluded • Theses/dissertations excluded • Foreign language books excluded • 20% of ILL requests • ILL borrowing transactions 1998-2002 • Cancelled (owned) requests excluded • Circulations 1995-2003 • Items circulating > 1 time

7. Numbers • 970,784 books held in WorldCat • 318,517 books circulated 1998-2002 • 1,638,740 circulation transactions 1995-2003 • 22,064 ILL borrowing requests for books 1998-2002

8. Data Manipulation • ILL requests lacked LCC numbers • Mapped to WorldCat records by OCLC # • All data sets mapped by LCC: • 600+ North American Title Count (NATC) subject categories • 24 Research Libraries Group (RLG) Conspectus Divisions

9. Results • Overall holdings • No multiple copies counted, just titles • Derived from OCLC WorldCat, but could be pulled locally

10. Interpretation • Overall holdings • Some subjects have very high publishing output • Some subjects strongly dominated by journal literature or other non-book formats • Scores

11. Conspectus Subject Category Holdings Language, Linguistics, and Literature 193,781 History and Auxiliary Sciences 126,797 Business and Economics 85,973 Engineering and Technology 58,377 Philosophy and Religion 50,024 Greatest Number of Holdings by Subject

12. Conspectus Subject Category Holdings Law 11,721 Chemistry 9,504 Anthropology 7,688 Physical Education and Recreation 7,067 Agriculture 6,490 Least Number of Holdings by Subject

13. Results • Average transactions per item • Transactions in a subject • Items held in a subject • Transactions/items = average transactions per item • Example: 10,000 transactions, 5,000 items, average 2 transactions per item

14. Interpretation • Average transactions per item • High average: 7.4 circs per item • Extremely active subject area • Where is activity occurring? • Low average: 3.1 circs per item • Low check out rate • Is collection relevant? What kind of usage?

15. Conspectus Subject Category Circ Trans-actions Circ Items Trans-actions per Item Music 53,855 7,230 7.4 Computer Science 35,378 5,202 6.8 Sociology 106,724 17,809 6.0 Physical Education and Recreation 14,432 2,409 6.0 Art and Architecture 106,186 17,962 5.9 Greatest Number of Transactions per Item by Subject

16. Conspectus Subject Category Circ Trans-actions Circ Items Trans-actions per Item Business and Economics 102,587 23,027 4.5 Political Science 52,108 11,745 4.4 Law 15,929 3,638 4.4 Education 37,425 8,870 4.2 Library Science, Generalities, and Reference 15,595 4,972 3.1 Least Number of Transactions per Item by Subject

17. Results • Percentage of items circulated • Total items held in a subject • Items circulated in a subject • Circulated /items held in subject = percentage circulated • Example: 8,000 items held in subject, 2,000 items circulated = 25% items circulated

18. Interpretation • Percentage of items circulated • High percentage: 43.3% • Almost half of books circulated during study • Circulation is widely distributed across subject • Low percentage: 14.9% • Less than one quarter of books circulated • Circulation is very narrow, or use is mostly in-house

19. Conspectus Subject Categories Holdings Circ Items % Items Circulated Anthropology 7,688 3,331 43.3% Sociology 43,437 17,809 41.0% Computer Science 12,958 5,202 40.1% Psychology 13,406 5,376 40.1% Music 18,476 7,230 39.1% Performing Arts 11,921 4,661 39.1% Highest Percentage of Items Circulated by Subject

20. Conspectus Subject Category Holdings Circ Items % Items Circulated Language, Linguistics, and Literature 193,781 56,631 29.2% Chemistry 9,504 2,775 29.2% Business and Economics 85,973 23,027 26.8% Education 33,314 8,870 26.6% Library Science, Generalities, and Reference 33,327 4,972 14.9% Lowest Percentage of Items Circulated by Subject

21. Results • Ratio of holdings to ILL requests • Comparing apples to oranges, but still useful • Total items in subject • ILL requests in subject • Items in subject : ILL requests = ratio • Example: 12,000 items in subject, 1,000 requests = 12:1

22. Interpretation • Ratio of holdings to ILL requests • High ratio: 9:1 • Many requests in subject area • Evaluate whether local collection serving user needs • Low ratio: 144:1 • Very few requests in subject area • Various interpretations

23. Conspectus Subject Category Holdings ILL Items Holdings : ILL Ratio Agriculture 6,490 713 9.1 : 1 Medicine 36,501 2,496 14.6 : 1 Physical Education and Recreation 7,067 387 18.3 : 1 Engineering and Technology 58,377 2,334 25.0 : 1 Sociology 43,437 1,673 26.0 : 1 Highest ILL Ratio by Subject

24. Conspectus Subject Category Holdings ILL Items Holdings : ILL Ratio Physical Sciences 28,497 390 73.1 : 1 Education 33,314 447 74.5 : 1 Political Science 35,764 457 78.3 : 1 Language, Linguistics, and Literature 193,781 2,475 78.3 : 1 Library Science, Generalities, and Reference 33,327 231 144.3 : 1 Lowest ILL Ratio by Subject

25. Example: Sociology • Medium number of holdings: 43,437 • High transactions per item: 6.0 • High percentage items circulated: 41.0% • High ratio holdings : ILL requests: 26.0:1 • Interpretation

26. Circulations by Date

27. Interlibrary Loans by Publication Date

28. Limitations of Study • Time consuming • Materials used in library excluded • Circulation and ILL data for limited time period • Discipline and status of borrowers not identified • Only English monographs analyzed

29. Transition From Research to Practice • CU-Boulder data collection methods revised • Reconfigure ILS data to capture • Circulations/item/year • Circulations by subjects identified by bibliographers • Revised ILL request forms to require discipline and status

30. Gathering Your Data • Define a book • Include or exclude • Government documents • Dissertations • Microprint • Non-circulating items • Foreign language • Branch library collections • Make sure definition of book matches for every data set • Identify a time period • What data are available for all three data sets?

31. Gathering Your Data • Determine what you need • Holdings: bibliographic records (not item records) • Circulations: transaction tallies, including dates • ILL borrowing: initiated requests

32. Analyzing Your Data • OCLC numbers for all items • Combine data sets into a database (e.g. Access) • Use LCCs to map to Conspectus and NATC

33. Questions? Lynn Silipigni Connaway Consulting Research Scientist, OCLC, Inc. Lynn_connaway@oclc.org Heather Wicht Electronic Resources Librarian, CU Boulder heather.wicht@colorado.edu