levine-clark, michael, and kari paulson, “10,000 libraries, 4 years: a large-scale study of ebook...

10,000 Libraries, 4 Years: A Large-Scale Study of eBook Usage and

How You Can Use the Data to Move Forward

NASIG Annual ConferenceFort Worth

May 3, 2014

Michael Levine-ClarkUniversity of Denver

Previous Presentations

• Different data set – All books available across a four-year period

(ebrary) or three-year period (EBL) ending in 2013– No information about time spent in book– No information about number/type of institutions

with access to a particular title• Tested the methodology

http://www.slideshare.net/MichaelLevineClark/presentations



Data Overview

All e-books from ebrary and EBL • Usage for 2013• Worldwide• Three library types– Academic– Public– Special

Important Caveat

• ebrary includes 2013 usage data for titles available in 2013

• EBL includes 2013 usage data for all titles whether or not available in 2013– Titles no longer available– Titles made available in early 2014– Will be updated before the white paper

Usage Definitions• Session– Any time that a user interacts with an e-book

• Page View– A count of the number of pages examined

• Download– A download of the entire book

• Usage Time– Measured in seconds, the amount of time spent

looking at the book

Some aspects of usage aren’t comparable

• ebrary has far more libraries than EBL– Averages and totals only useful when comparing

within one aggregator• EBL includes titles not available during the

usage period• There may be some platform differences that

drive usage in different ways:– More downloads per session on EBL = fewer pages

viewed – EBL has a landing page and ebrary doesn’t.

What can we learn by examining usage on such a large scale?

• Are we collecting the right things?• Does quality matter?• Are there general patterns by subject?• Can we identify disciplinary preferences?• What are the best ways to measure use?• Can those patterns and preferences help

shape our collections and guide our services?

The Complete Data Set

Academic Public Special400,000

410,000

420,000

430,000

440,000

450,000

460,000

Academic Public Special0

50,000

100,000

150,000

200,000

250,000

300,000

Academic Library eBooks

• 280,008 titles– Available on average in 724

libraries

• 278,428 titles with LCCN– Available on average in 727

libraries

• 456,298 titles– Available on average in 50

libraries

• 406,311 titles with LCCN– Available on average in 60

libraries

Academic Library eBook Usage

278,428 titles with LCCN

On average in 2013, each title:– Was held by 726.6 libraries– Had 424.9 sessions– Had 6,623.1 page views– Had 14.7 downloads– Was viewed for 54,556.8

seconds (15.2 hours)


On average in 2013, each title:– Was held by 60.3 libraries– Had 22.5 sessions– Had 466.6 page views– Had 2.9 downloads– Was viewed for 229.1

seconds (3.8 minutes)

Averages are per title across all libraries.

Academic Library eBook Usage


On average in 2013, at each library, each title:

– Had 0.58 sessions– Had 9.12 page views– Had 0.02 downloads– Was viewed for 75.09 seconds


On average in 2013, at each library, each title:

– Had 0.37 sessions– Had 7.74 page views– Had 0.05 downloads– Was viewed for 3.80 seconds

Average Number of Libraries with Title Available by Discipline

Arts & Humani-

ties

Social Sciences

STEM0

100

200

300

400

500

600

700

800

900

ebrary

Arts & Humani-

ties

Social Sciences

STEM0

10

20

30

40

50

60

70

EBL

Title Availability: Ebrary

E F U D M Z V B C P H J N A Q K G S R T L0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

Average number of academic libraries with title available

Title Availability: EBL

L H J G N Z E M Q D T R K C B S F V U A P0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Average number of academic libraries with title available

ARE THESE THE RIGHT BOOKS?

Sessions Compared to Availability

Arts &

Humanities

Socia

l Scie

nces

STEM

0100200300400500600700800900

ebrary

AvailabilitySessions

Arts &

Humanities

Socia

l Scie

nces

STEM

0

10

20

30

40

50

60

70

EBL


On this and the next two slides, sessions are multiplied to fit scale (ebrary X 1000, EBL X 100)

Sessions Compared to Availability: Ebrary

E F U D M Z V B C P H J N A Q K G S R T L0.0

200.0

400.0

600.0

800.0

1000.0

1200.0

1400.0

1600.0


Sorted by average availability (number of libraries with access)

Sessions Compared to Availability: EBL

L H J G N Z E M Q D T R K C B S F V U A P0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0


Sorted by average availability (number of libraries with access)

DO HIGHER-QUALITY E-BOOKS GET USED MORE?

University Press Books

• A proxy for quality• ebrary – 41,177 titles• EBL – 39,021 titles

Do better books get used at a higher rate?

University Press Title Availability by Discipline

19075

13260

7533

Arts & Humanities Social Sciences

STEM

16065

11649

8183

Arts & HumanitiesSocial SciencesSTEM

Overall Usage: titles with at least one session

All Titles with LCCN

University Press0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

97.3% 99.5%

ebrary


University Press Titles

0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

66.8%74.8%

EBL

Overall Usage: average sessions per title per institution



0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.584 0.615

ebrary



0

0.1

0.2

0.3

0.4

0.5

0.373 0.387

EBL

Overall Usage: average page views per title



0.001.002.003.004.005.006.007.008.009.00

10.00 9.12 9.51

ebrary



0123456789

10

7.748.33

EBL

Overall Usage: titles viewed at least once



0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

99.3% 99.3%

ebrary



0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

65.6%73.7%

EBL

Overall Usage: time per title (in seconds)



0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00

100.00

75.1083.73

ebrary



0.000.501.001.502.002.503.003.504.004.505.00

3.804.35

EBL

University Press Summary

• Used at a higher rate across all categories.• Does this mean that users are seeking out

quality books?

BROAD DISCIPLINARY DIFFERENCES

The Disciplines

HumanitiesB (Philosophy, Religion) excluding BF (Psychology)C, D, E, F (History)M (Music)N (Fine Arts)P (Language & Literature)

Social Sciences BF (Psychology)H (Social Sciences)J (Political Science)K (Law)L (Education)U, V (Military, Naval Sciences)

STEMQ (Science)R (Medicine)S (Agriculture)T (Technology)

Percentage of Titles Usedebrary

Discipline % Titles with a Session

% Titles Viewed % Titles Downloaded

Humanities 96.62% 96.35% 34.64%

Social Sciences 98.61% 98.40% 32.06%

STEM 96.38% 96.06% 30.45%

Baseline (all titles with an LCCN) 97.27% 97.01% 32.24%

Percentage of Titles UsedEBL

Discipline % Titles with a Session

% Titles Viewed % Titles Downloaded

Humanities 62.76% 61.63% 34.61%

Social Sciences 69.97% 69.09% 43.22%

STEM 67.27% 65.79% 40.19%

Baseline (all titles with an LCCN) 66.76% 65.59% 39.58%

Average Usageebrary

Discipline Sessions Page Views Full Downloads Time (Seconds)

Humanities 0.48 7.32 0.0156 63.41

Social Sciences 0.68 10.45 0.0234 87.88

STEM 0.59 9.61 0.0225 72.99

Baseline (all titles with LCCN)

0.58 9.12 0.0203 75.09

Average UsageEBL

Discipline Sessions Page Views Full Downloads Time (Seconds)

Humanities 0.29 5.90 0.0338 3.05

Social Sciences 0.44 8.95 0.0561 4.46

STEM 0.36 7.77 0.4858 3.58

Baseline (all titles with LCCN)

0.37 7.74 0.4746 3.80

Actions Per Sessionebrary

Discipline Views Per Session

Downloads Per Session

Time Per Session

Humanities 15.12 0.032 130.61

Social Sciences 15.42 0.035 129.42

STEM 16.40 0.384 124.06

Baseline (all titles with an LCCN) 15.59 0.035 128.05

Actions Per SessionEBL

Discipline Views Per Session

Downloads Per Session

Time Per Session

Humanities 20.53 0.118 10.62

Social Sciences 20.15 0.126 10.05

STEM 21.81 0.136 10.06

Baseline (all titles with an LCCN) 20.74 0.127 10.18

Disciplinary Summary

• Social sciences far outperform humanities and STEM in two categories– Percentage of books used– Average amount of use

• STEM outperforms the others in actions per session• Readers in the humanities spend more time in the

book per session

MEASURING PREDICTED USE

Performance Relative to Predicted Use

H B J R D L K M E G Q N C A S V Z U F T P0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

% of available % of titles with a session


H R L N D M E A B G C Z V J U F S K P T Q0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

% of Titles Available % of Sessions


H L T J R N E M S D V A C G Z U B F K Q P0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

% of Titles Available % of Titles with a Session


H L R G J N A C V Z M U S E F K D B T P Q0.00%

5.00%

10.00%

15.00%

20.00%

25.00%

30.00%

% of Titles Available % of Sessions

INTENSIVE / EXTENSIVE USE

Breadth vs Depth

PERCENTAGE OF TITLES USED

AVER

AGE

AMO

UN

T O

F U

SE

ebrary Sessions – Avg and % Broad (high %) andDeep (more usage of each title)

Narrow (low %) andShallow (low usage of each title)

Broad (high % and Shallow (low usage of each title)

Narrow (low %) but Deep (more usage of each title)

EBL Sessions – Avg and % Narrow (low %) but Deep (more usage of each title)

Broad (high %) andDeep (more usage of each title)



ebrary Page Views – Avg and % Narrow (low %) but Deep (more usage of each title)




EBL Page Views – Avg and % Narrow (low %) but Deep (more usage of each title)




ebrary Downloaded – Avg and % Narrow (low %) but Deep (more usage of each title)




EBL Downloaded – Avg and % Narrow (low %) but Deep (more usage of each title)




CAN WE DETERMINE LEVEL OF IMMERSION IN A BOOK?

Page Views Per Session

T Q F N R D H G C E M L Z P J B S K U A V0.002.004.006.008.00

10.0012.0014.0016.0018.0020.00

15.86

Seconds Per Session (Time in the Book)

E D F U H J M R G P K L C Q T N B S Z V A0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

128.05

Page Views Per Session

F N T M V E Q R K G D A C H P S J B Z U L0.00

5.00

10.00

15.00

20.00

25.00

30.00

20.74

Seconds Per Session (Time in the Book)

F E D K J M C G V A U Q H R P T B N L S Z0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

10.18

Summary: Level of Immersion

• Users spend the most time (in seconds) in history books (D, E, F)

• Users examine a lot of pages in technology books (T) but spend a relatively small amount of time

CONCLUSIONS

There are many ways to measure use

• Difference from predicted use• Depth vs breadth– Books used a lot vs a lot of books used

• Type of use (session, view, download)• Amount of use per session

Quality Matters

• University press books used at a higher rate by all measures

• Users appear to be making some judgment about quality

There are clear (but nuanced) differences by subject

• Two examples– F (History, Americas) • Low usage as % of available F titles• Low average usage rate• Very poor performance relative to availability of F titles• High # of page views by session• Lots of time in the book

– L (Education)• High usage as % of available L titles• High average usage rate• Very strong performance relative to availability of L titles• Relatively low # of page views by session/time in book

How do we use these observations to build better collections and

better serve our users?

White Paper…

…coming soon

• Merged data (EBL and ebrary)• EBL – titles available in 2013• Analysis by library type• Will be on the EBL and ebrary web sites

Plus future publications and presentations

Thank You

Michael Levine-ClarkAssociate Dean for Scholarly Communication and

Collections ServicesUniversity of Denver [email protected]

http://www.slideshare.net/MichaelLevineClark

http://www.slideshare.net/MichaelLevineClark

levine-clark, michael, and kari paulson, “10,000 libraries, 4 years: a large-scale study of ebook...

Education

titles available

available titles

titles ebl

ebl usage

title available

ebl availability sessions

ebrary availability

average number of libraries