collection analysis with circulation, ill and collection statistics: a follow-up presentation lynn...

Collection Analysis with Circulation, ILL and Collection Statistics:

A Follow-up Presentation

Lynn Silipigni ConnawayOCLC, Inc.

Heather WichtUniversity of Colorado

Jennifer KnievelUniversity of Colorado

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

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

Purpose of Study

Compare subject distribution• CU-Boulder holdings• ILL borrowing requests• Circulation

Local Systems

Software• Innovative Interfaces• CLIO Database

Data Gathering Methods• Innovative: Create Lists• CLIO: Microsoft Access Queries

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

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

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

Results

Overall holdings• No multiple copies counted, just titles• Derived from OCLC WorldCat, but could be

pulled locally

Interpretation

Overall holdings• Some subjects have very high publishing

output• Some subjects strongly dominated by journal

literature or other non-book formats• Scores

Greatest Number of Holdings by Subject

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

Least Number of Holdings by Subject

Conspectus Subject Category Holdings

Law 11,721

Chemistry 9,504

Anthropology 7,688

Physical Education and Recreation 7,067

Agriculture 6,490

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

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?

Greatest Number of Transactions per Item by Subject

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

Least Number of Transactions per Item by Subject

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

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

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

Highest Percentage of Items Circulated by Subject

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%

Lowest Percentage of Items Circulated by Subject

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%

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

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

Highest ILL Ratio by Subject

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

Lowest ILL Ratio by Subject

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

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

Circulations by Date

1975 - 19793%

1980 - 19846%

1900-19494%

No Valid Date2%

Before 19001%2000 - 2004

5%

1950-197418%

1995 - 199925%

1985 - 19899%

1990 - 199427%

Interlibrary Loans by Publication Date

No Valid Date3%

1950-197412%

1975 - 19798%

1980 - 19848%

1985 - 198912%

1990 - 199417%

1995 - 199924%

2000 - 20047%

Before 19003%

1900-19496%

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

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

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?

Gathering Your Data

Determine what you need• Holdings: bibliographic records (not item

records)• Circulations: transaction tallies, including dates• ILL borrowing: initiated requests

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

Questions?

Lynn Silipigni ConnawayConsulting Research Scientist, OCLC, Inc.Lynn_connaway@oclc.org

Heather WichtElectronic Resources Librarian, CU Boulderheather.wicht@colorado.edu