Strategic Use of Circulation Data

Moving Beyond the Basics

Richard EntlichCollection AnalystCornell University Library

Charleston Conference, November 3, 2011

Value of Circulation Data in Collection Management

• Recognized many years ago• First proposed as a means to

help cope with overcrowded stacks

• Move little used materials to remote storage facility

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Quotes from an Early Proponent of the Strategic Use of Circulation Data

“Completeness can no longer be the ideal of any library.”

“All signs indicate that the flood of printed material has by no means reached its height.”

“It is not a good use of the educational resources of an institution to enlarge its library building to make new space for books in use, when books that are very seldom used can be stored in inexpensive buildings on cheap land.”

Source

Charles William Eliot (President of Harvard University)

“The Division of a Library into Books in Use, and Books Not in Use, with Different Storage Methods for the Two Classes of Books.”

Library Journal 27, no. 7:51-56, 1902

More Wisdom from Charles Eliot

“The means of just discrimination between books in use and books not in use are not easy to discern or to apply; but I maintain, nevertheless, that the search for these means should be diligently prosecuted, and that every reasonable suggestion of means of discrimination deserves careful attention.”

What is use and how do we measure it?• We recognize two common classes of use for print

materials• In-building use (“browsing”) • Out of building use (“circulation”)

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Photo credit: Brendan Murphy http://www.flickr.com/photos/29501884@N04/4552647815/

Browsing

• Evidence of browsing may be hard to detect• As an activity, it is difficult to measure accurately and

consistently• Measurement of browsing, if done at all, can vary

widely, even between libraries within an institution or in the same library over time

Circulation

• The “gold standard” for measuring use of books• It too suffers from a lack of standardization

• What transactions are included? (e.g., ILL)• What are loan periods for different user groups and

materials?• What materials don’t circulate at all?• Is there a limit on renewals?

See “A Look at Circulation Statistics” by Jeff Luzius Journal of Access Services, Vol. 2(4) 2004, pp.15-22

Measuring Use of Books: The Bottom Line

• Circulation is the best measure we have, though it has limitations

• There is some evidence that circulation and browsing are well-correlated

• Comparing circulation between institutions may be of little value, except in the broadest terms

• Comparing circulation within an institution should be meaningful, as long as policies and procedures are fairly consistent across units and over time

A Challenge from Charleston Past• QUESTIONS FOR LIBRARIANS WHO DO

COLLECTION DEVELOPMENT• Do you get or use any circulation data in making

decisions about what books to buy?• If you do get circulation data, does it specifically

pinpoint what's happening in your subject area?• Do you have circulation data time series for your

subject(s)?• Do you see any need for this information?

(From Charles Hamaker, Charleston Conf., 1994)

More Wisdom from Charles Hamaker

“We somehow assume the circulation librarian is ‘responsible’ for circulation data. Few of us have figured out how to use these [automated library systems] to see if they can help us make better decisions about what to buy, or even to see if they tell us what kind of a job we have done with what we did buy.”

Other Potential Strategic Applications of Circulation Data

• For what titles should we buy multiple copies?• What materials should be owned vs borrowed vs

rented?• What loan policies and periods should apply to what

materials?• In what library building should certain materials be

housed?

Current Challenges Facing Libraries Suggest We Must Adopt a More Quantitative Approach

• Increased scrutiny of library budgets and demands for accountability

• Widening gap between the universe of published output and collection budgets

• Physical space constraints• The shift from speculative (“just-in-case”) to demand-

driven (“just-in-time”) acquisitions

Early Generation Library Automation Systems

• Browse and circulation totals at the title level• No individual transaction data• Transactions were not date and time stamped• Little or no user data• Inability to distinguish internal library use or ILL from

community use• Limited management reporting capability, often

requiring advanced programming skills

Recent Generation Library Automation Systems

• Detailed circulation transaction records retained• Time/location of all charges and discharges• Patron groups (distinguish ‘pseudo-patrons’)• Renewal counts

• More flexible (though not necessarily easy to use) reporting functions

Basic Data Requirements for Circulation Analysis

1. A set of bibliographic data pertaining to print monographs owned by the library, usually subject to certain selection criteria

2. The set of circulation transactions that correspond to the items in set one

Caveats: Bibliographic Records

• Limited to books?• Limited to print?• When first available to circulate?• Part of a circulating collection?• Lost or withdrawn?• Do records support analysis?

Caveats: Circulation Records

• Completed vs in process transactions• Variable loan periods, esp. short-term reserves• What to do about renewals?• Identification of ‘pseudo-patron’ transactions• Handling of ILL transactions

“Beyond Basic” Circulation Analysis

• Trend or Time Series Analysis

• Ratio Analysis

• Integration of non-ILS data

Time Series Study: Time to First Circulation

• Basic Recipe• Gather data on a set of books acquired in a similar time

frame• Gather circulation records for the above set• Isolate the set of first circulations for each• Compute time (in months) from acquisition to first circulation• Analyze as desired

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LC Top Class - DescriptionAvg Months to First Circ

Total Items

A - General Works 43.4 57V - Naval Science 43.2 60Z - Library Science 33.8 300C - Auxiliary Sciences of History 33.2 299F - History: United States Local and Latin America 32.8 814D - History: General and Outside the Americas 32.5 4459K - Law 32.3 1524B - Philosophy, Psychology, Religion 30.4 3859U - Military Science 28.6 280P - Language and Literature 28.6 8135N - Fine Arts 27.5 2585J - Political Science 25.5 1214M - Music 23.7 750G - Geography 23.2 1134H - Social Sciences 22.3 7138L - Education 21.9 718E - History: United States 21.0 925R - Medicine 18.8 1059S - Agriculture 18.3 1012T - Technology 18.2 1967Q - Science 15.7 3169

Time Series Study: Cumulative Volume Circulation

• Recipe• Gather data on a set of books acquired in a similar time

frame• Gather circulation records for the above set• Isolate the set of first circulations for each• Count the number of first circulations for each year• Calculate cumulative totals for each year• Analyze as desired

Source: Use of Library Materials: The University of Pittsburgh Study by Kent, et al. 1979

Time Series Study: Circulation Consistency

• Recipe• Gather data on a set of books acquired in a similar time

frame• Gather circulation records for the above set• Group records by year of circulation• Cross tabulate desired parameters

ITEM_IDLC Top Class 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Total Circ Years

5952322 K 0 0 0 0 0 0 0 0 1 0 0 15952325 K 0 1 0 0 0 0 0 0 0 0 0 15952328 K 0 1 0 0 0 0 0 0 0 0 0 15952337 G 0 0 0 0 0 0 1 0 0 1 0 25952339 N 1 1 1 1 0 1 0 1 0 0 0 65952341 Q 0 0 0 0 1 0 0 0 0 0 0 15952345 H 1 1 0 0 0 0 0 0 0 0 0 25952346 N 1 0 0 0 0 0 0 0 0 0 0 1 THE FLASH IN THE PAN5952350 E 1 0 0 0 1 1 0 0 0 1 0 45952354 H 0 0 0 0 0 1 0 1 0 0 0 25952357 E 1 0 1 0 0 0 0 0 0 0 1 35952369 P 0 0 0 0 0 0 0 0 0 1 0 15952373 H 1 1 1 1 1 1 1 1 1 0 1 10 THE STEADY PERFORMER5952375 H 1 0 0 1 0 0 1 1 0 0 0 45952380 P 0 1 0 1 0 0 0 0 0 0 0 25952383 B 0 0 0 0 1 0 0 0 0 0 0 15952384 Q 1 1 1 1 0 1 1 0 0 0 0 65952385 Q 0 0 0 1 0 0 0 0 0 0 0 15952386 P 1 1 0 0 0 0 0 0 0 0 0 25952422 P 0 0 0 0 1 0 0 0 0 0 0 15952423 P 1 1 0 0 0 0 0 0 0 0 0 25952424 B 0 0 0 0 0 0 0 0 0 1 1 2 THE LATE BLOOMER5952433 H 1 0 0 0 0 0 0 0 0 0 0 15952437 K 1 0 0 0 0 0 0 0 0 0 0 15952438 L 1 0 1 0 1 1 0 1 0 1 0 65952445 B 1 1 1 1 1 1 1 1 1 0 0 95955982 H 1 1 0 0 0 0 0 0 0 1 1 4 THE COMEBACK KID

LC Top Class - DescriptionAverage of Circ Years

Total Items

Q - Science 3.58 3169S - Agriculture 3.48 1012E - History: United States 3.25 925G - Geography 3.18 1134M - Music 3.09 750R - Medicine 3.08 1059T - Technology 3.06 1967N - Fine Arts 3.04 2585J - Political Science 2.95 1214H - Social Sciences 2.86 7138L - Education 2.80 718P - Language and Literature 2.75 8135B - Philosophy, Psychology, Religion 2.57 3859F - History: United States Local and Latin America 2.46 814C - Auxiliary Sciences of History 2.37 299D - History: General and Outside the Americas 2.28 4459Z - Library Science 2.23 300U - Military Science 2.21 280A - General Works 2.19 57K - Law 2.09 1524V - Naval Science 1.77 60

Ratio Analysis: Circulation by Language• From a study of historical circulation of books in a

particular LC subclass, by language• At first glance, the data doesn’t seem very dramatic

Language Holdings Total Circ

No. of Volumes that Circulated

% of Historical Circulation

% of Volume Circulation

English 7417 38974 5637 95.6% 86.1%French 1055 840 369 2.1% 5.6%German 1018 468 262 1.1% 4.0%Russian 772 79 56 0.2% 0.9%Spanish 481 180 96 0.4% 1.5%Italian 171 67 40 0.2% 0.6%Portuguese 98 46 25 0.1% 0.4%Greek 49 40 22 0.1% 0.3%

French German Russian Spanish Italian Portuguese Greek Total0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

% of Historical Circulation for non-English Volumes with the Largest Holdings

French German Russian Spanish Italian Portuguese Greek0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

% of Volume Circulation for non-English Volumes with the Largest Holdings

Whether plotted as historicalor volume circulation, severallanguages show similar levelsof use, relative to the whole.

But the ratios tell a different story:An “Enthusiasm Gap”

Language%Holdings / %HistoricalCirc

%Holdings / %VolumeCirc

French 4.50 1.65German 7.80 2.24Russian 35.05 7.94Spanish 9.58 2.89Italian 9.15 2.46Portuguese 7.64 2.26Greek 4.39 1.28

French German Russian Spanish Italian Portuguese Greek0

5

10

15

20

25

30

35

40

% Holdings to % Total Circulation Ratio for non-English Volumes with the Largest Holdings

French German Russian Spanish Italian Portuguese Greek0

1

2

3

4

5

6

7

8

9

% Holdings to % Volume Circulation Ratio for non-English Volumes with the Largest Holdings

External Data: “Circulation Snapshot”• A frozen moment in a

continuous stream of data

• Combines ILS data with human resources data for a much richer demographic analysis of users• Profiles the users of print• Identifies relationships between users and materials

• impact of characteristics like status, department, field of study, and college affiliation on borrowing habits

• breakdown of subjects, languages, dates of publication by user groups

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Some Strategic Applications of Snapshot Data• For Unit Library Review process

• From which depts/fields do borrowers of libraries come?• Which libraries do members of affiliated depts/fields use?

• For Print Collection Usage Task Force review process• LC class user analysis by department and graduate field• Department/grad field usage breakdown by LC class• Circulation time and renewals by patron status

• Other potential uses• User breakdown by publication date (for off-site transfer

decision-making)• Inform individual subject selectors about usage in their

domain

For a detailed description of the circulation snapshot process and its use, see

Richard Entlich, “Focus on Circulation Snapshots: A Powerful Tool for Print Collection Assessment” in

Proceedings of the 2010 Library Assessment Conference, October 24–27, 2010, Baltimore, Maryland, pp. 703-13.

http://libraryassessment.org/bm~doc/proceedings-lac-2010.pdf

Questions?

Comments?

Discussion?

To contact me: rge1@cornell.edu