The document discusses findings from analyzing usage data of over 750,000 e-books from 2010-2013. Key findings include: - University press and books with LC classifications tended to see higher usage rates. - Social sciences showed the highest percentage of titles used and average usage. Humanities performed better than STEM on ebrary but worse on EBL. - Certain disciplines like education, social sciences, and history showed better than expected usage rates while science, language/literature, and military science showed worse than expected usage. - Usage can be categorized as either intensive (higher average usage of titles used) or extensive (higher percentage of titles used), with different patterns seen across disciplines and platforms.

1. Diving Into E-Book Usage: Assessing
the Swell of Information
Philadelphia
January 24, 2014
Michael Levine-Clark
Associate Dean for Scholarly Communication and Collections Services
University of Denver Libraries

2. What can we learn by examining usage of
750,000+ e-books?
•
•
•
•
•
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?

3. The Data Set
• 2010
– 435,417 titles
– 5,295 libraries
• 2011
– 537,743 titles
– 5,899 libraries
• 2012
– 667,427 titles
– 6,474 libraries
• 2013 (through Sept 4)
– 776,060 titles
– 7,118 libraries
• 2011
– 225,448 titles
– 291 libraries
• 2012
– 320,796 titles
– 411 libraries
• 2013 (through Sept 9)
– 378,530 titles
– 587 libraries

4. Combined Data
• 2010-Sept 2013
• 435,417 titles
• 304,417 with an LC call
number
• 32,988 university press
titles
• 2011-Sept 2013
• 217,457 titles
• 210,539 titles with an LC
call number
• 21,089 university press
titles

5. Usage Definitions
• Session
– Any time that a user interacts with an e-book
• View
– A count of the number of pages examined
• Print
– ebrary: counts the act of printing, regardless of
how many pages
– EBL: counts each page printed, even if printed as a
range

6. Usage Definitions
• Copy
– Any instance of copying a portion of text
• Download
– A download of the entire book

7. Some aspects of usage aren’t
comparable
• ebrary has far more libraries than EBL, and an
extra year of data
– Averages and totals only useful when comparing
within one aggregator
• Some usage not counted the same
– Printing

8. AVERAGE AMOUNT OF USE
Breadth vs Depth
PERCENTAGE OF TITLES USED

9. DO HIGHER-QUALITY E-BOOKS GET
USED MORE?

10. University Press Books
• A proxy for quality
• ebrary – 32,988 titles
• EBL – 21,089 titles
Do better books get used at a higher rate?

11. Overall Usage - Sessions
• At least one session
– 69.16% of titles
– 91.72% of titles with an LC
call number
– 93.76% of university press
titles
• On average (across all
libraries)
– 147.43 sessions per title
– 208.64 sessions per title with
an LC call number
– 339.01 sessions per title for
university press titles
• At least one session
– 88.33% of titles
– 89.00% of titles with an LC
call number
– 93.80% of university press
titles
• On average (across all
libraries)
– 69.39 sessions per title
– 70.99 sessions per title with
an LC call number
– 76.74 sessions per title for
university press titles

12. Overall Usage – Page Views
• Viewed at least once
– 69.15% of titles
– 91.70% of titles with an LC
call number
– 93.74% of university press
titles
• On average (across all
libraries)
– 2,245.23 views per title
– 3,174.31 views per title with
an LC call number
– 5,203.82 views per title for
university press titles
• Viewed at least once
– 87.30% of titles
– 88.01% of titles with an LC
call number
– 92.82% of university press
titles
• On average (across all
libraries)
– 1,310.39 views per title
– 1,341.91 views per title with
an LC call number
– 1,499.78 views per title for
university press titles

13. Overall Usage - Copies
• At least one title with a
section copied
– 35.84% of titles
– 49.82% of titles with an LC
call number
– 64.20% of university press
titles
• On average (across all
libraries)
– 27.56 copies per title
– 39.21 copies per title with an
LC call number
– 63.95 copies per title for
university press titles
• At least one title with a
section copied
– 37.13% of titles
– 37.92% of titles with an LC
call number
– 45.30% of university press
titles
• On average (across all
libraries)
– 92.00 copies per title
– 94.46 copies per title with an
LC call number
– 116.05 copies per title for
university press titles

14. Overall Usage - Printing
• At least one title with pages
printed
– 34.41% of titles
– 47.33% of titles with an LC
call number
– 64.95% of university press
titles
• On average (across all
libraries)
– 171.35 prints per title
– 244.32 prints per title with an
LC call number
– 461.27 prints per title for
university press titles
• At least one title with pages
printed
– 36.46% of titles
– 37.17% of titles with an LC
call number
– 42.25% of university press
titles
• On average (across all
libraries)
– 5.29 prints per title
– 5.43 prints per title with an LC
call number
– 5.57 prints per title for
university press titles

15. Overall Usage – Full Downloads
• At least one title
downloaded
– 24.35% of titles
– 34.42% of titles with an LC
call number
– 40.12% of university press
titles
• On average (across all
libraries)
– 2.77 downloads per title
– 3.95 downloads per title with
an LC call number
– 5.64 downloads per title for
university press titles
• At least one title
downloaded
– 59.12% of titles
– 59.83% of titles with an LC
call number
– 67.77% of university press
titles
• On average (across all
libraries)
– 9.34 downloads per title
– 9.54 downloads per title with
an LC call number
– 10.41 downloads per title for
university press titles

16. University Press Summary
• Used at a higher rate across all categories
BUT
• University press books may be available in
more libraries

17. BROAD DISCIPLINARY DIFFERENCES

18. The Disciplines
Humanities
B (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)
STM
Q (Science)
R (Medicine)
S (Agriculture)
T (Technology)

19. Percentage of Titles Used
ebrary
Discipline
% Titles with
a Session
% Titles
Viewed
% Titles
Copied
% Titles
Printed
% Titles
Downloaded
Humanities
92.05%
92.04%
52.50%
49.44%
40.87%
Social Sciences
92.70%
92.69%
55.44%
50.89%
36.40%
STM
90.19%
90.17%
42.90%
41.95%
27.53%
Baseline (all titles with an
LCCN)
91.72%
91.70%
49.82%
47.33%
34.42%

20. Percentage of Titles Used
EBL
Discipline
% Titles with
a Session
% Titles
Viewed
% Titles
Copied
% Titles
Printed
% Titles
Downloaded
Humanities
88.44%
87.19%
36.28%
33.24%
58.62%
Social Sciences
89.95%
89.12%
42.77%
42.69%
62.40%
STM
88.30%
87.35%
33.65%
33.91%
57.68%
Baseline (all titles with an
LCCN)
89.00%
88.01%
37.92%
37.17%
59.83%

21. Average Usage
ebrary
Discipline
Sessions
Page Views Copies
Prints
Full Downloads
Humanities
207.79
3122.16
36.86
235.16 3.95
Social Sciences
251.21
3766.11
54.65
283.03 4.74
STM
162.57
2570.70
24.33
211.63 3.16
Baseline (all titles with LCCN)
208.64
3174.31
39.21
244.32 3.95

22. Average Usage
EBL
Discipline
Sessions
Page Views Copies
Prints
Full Downloads
Humanities
54.18
999.12
69.48
3.85
6.76
Social Sciences
91.96
1694.91
124.34 7.63
12.54
STM
59.90
1192.46
81.51
4.20
8.32
Baseline (all titles with LCCN)
70.99
1341.91
94.46
5.43
9.54

23. Actions Per Session
ebrary
Discipline
Views Per
Session
Copies Per
Session
Prints Per
Session
Downloads
Per Session
Humanities
15.03
0.177
1.132
0.019
Social Sciences
14.99
0.218
1.127
0.019
STM
15.81
0.150
1.302
0.019
Baseline (all titles with an LCCN)
15.21
0.188
0.171
0.019

24. Actions Per Session
EBL
Discipline
Views Per
Session
Copies Per
Session
Prints Per
Session
Downloads
Per Session
Humanities
18.44
1.282
0.071
0.125
Social Sciences
18.43
1.352
0.083
0.136
STM
19.91
1.361
0.070
0.139
Baseline (all titles with an LCCN)
18.90
1.331
0.076
0.134

25. Disciplinary Summary
• Social sciences far outperform humanities and
STM in two categories
– Percentage of books used
– Average amount of use
• Humanities stronger than STM on ebrary
• STM stronger than humanities on EBL
• STM outperforms the others in actions per
session

26. MEASURING PREDICTED USE

27. Difference from Predicted Use
LC Class
% of eBooks
available
% of titles with
a session
Difference
A – General Works
0.19%
0.19%
0.00%
B – Philos, Psych, Religion
7.03%
6.88%
-0.16%
C – Aux Sciences of History
0.40%
0.41%
+0.01%
D – World History, etc.
3.70%
3.73%
+0.03%
E – History of the Americas
1.65%
1.71%
+0.06%
F – History of the Americas
1.96%
1.85%
-0.11%
G – Geog, Anthro, Rec
2.94%
3.01%
+0.07%
H – Social Sciences
21.98%
22.27%
+0.29%
J – Political Science
3.40%
3.50%
+0.10%
K – Law
3.33%
3.29%
-0.04%

28. Difference from Predicted Use
LC Class
% of eBooks
available
% of titles with
a session
Difference
L - Education
4.61%
4.80%
+0.19%
M - Music
0.81%
0.85%
+0.04%
N – Fine Arts
1.06%
1.10%
+0.04%
P – Language & Literature
10.87%
11.00%
+0.13%
Q - Science
13.09%
12.51%
-0.58%
R - Medicine
10.83%
10.73%
-0.10%
S - Agriculture
2.01%
2.08%
+0.07%
T - Technology
8.65%
8.69%
+0.04%
U – Military Science
0.69%
0.58%
-0.11%
V – Naval Science
0.12%
0.12%
0.00%
Z – Bibliography and LIS
0.67%
0.69%
-0.02%

29. % of titles used (breadth)

30. % of titles used (breadth)

31. % of overall usage (depth)

32. % of overall usage (depth)

33. Performance Compared to Expected Use
Better than expected (top five)
Worse than expected (bottom five)
•
•
•
•
•
•
•
•
•
•
H (Social Sciences)
L (Education)
E (History of the Americas)
D (World History)
G (Geography,
Anthropology, Recreation)
Q (Science)
P (Language & Literature)
F (History of the Americas)
T (Technology)
U (Military Science)

34. INTENSIVE / EXTENSIVE USE

35. ebrary Sessions – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

36. EBL Sessions – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

37. ebrary Page Views – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

38. EBL Page Views – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

39. ebrary Copied – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

40. EBL Copied – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

41. ebrary Printed– Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

42. EBL Printed– Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

43. ebrary Downloaded – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

44. EBL Downloaded – Avg and %
Narrow (low %) but
Deep (more usage of
each title)
Narrow (low %) and
Shallow (low usage of
each title)
Broad (high %) and
Deep (more usage of
each title)
Broad (high % and
Shallow (low usage of
each title)

46. Summary of Performance Trends
• Broad and Deep
– G (Geog and Anthro), H (Social Sciences), L (Education), N (Fine
Arts)
• Broad
– D (World History), J (Political Science), M (Music)
• Narrow
– R (Medicine)
• Shallow
– P (Lang & Lit), S (Agriculture), T (Technology), Z (Bibliography &
LIS)
• Narrow and Shallow
– F (History of the Americas), Q (Science), U (Military), V (Naval)

47. TYPES OF USE PER SESSION

48. Page Views Per Session - ebrary
18.00
17.00
16.00
15.21
15.00
14.00
13.00
12.00
11.00
10.00
T
F
E Q R C G H D N
J M P B K
L U A S V Z

49. Page Views Per Session - EBL
24.00
22.00
20.00
18.90
18.00
16.00
14.00
12.00
10.00
F N T R M A E Q G C H D S B K P V
J
L
Z U

50. Copies per Session - ebrary
0.350
0.300
0.250
0.200
0.188
0.150
0.100
0.050
0.000
K
J
H C G L
E
F B D R P U S M T N Z V A Q

51. Copies Per Session - EBL
2.500
2.000
1.500
1.331
1.000
0.500
0.000
A K U C
J
B Q T V
L
R P N H S
Z D F
E G M

52. Prints Per Session - ebrary
1.800
1.600
1.400
1.200
0.171
1.000
0.800
0.600
Q K
J
C T B Z U D P R
F H L
S
E A V M G N

53. Prints Per Session - EBL
0.100
0.090
0.080
0.076
0.070
0.060
0.050
0.040
0.030
L
K A V R H B
J
U G Z
P C N S D F
E
T M Q

54. Downloads Per Session - ebrary
0.030
0.028
0.026
0.024
0.022
0.020
0.019
0.018
0.016
0.014
0.012
0.010
V U T B Q C
S
L
Z D H P M K N E
J
R
F G A

55. Downloads Per Session - EBL
0.200
0.180
0.160
0.140
0.134
0.120
0.100
0.080
0.060
0.040
V Z U S
T Q L N K H
J
C G B D P R A M F
E

56. Use Per Session Summary
• Very slight differences in some categories
• Some subjects do have greater activity during each
session than others
• Some big fluctuations
– Some subjects may not have enough titles to measure
copies, prints, downloads meaningfully.
• Five best subjects across all four categories of usage:
– B (Philos, Psych, Rel), C (Aux Sciences of History), K
(Law), T (Technology), U (Military Science)
• Five worst subjects:
– G (Geog, Anthro, Rec), M (Music), P (Lang & Lit), S
(Agriculture), Z (Bibliography)

57. CAN WE DETERMINE LEVEL OF
IMMERSION IN A BOOK?

58. If more pages are viewed per session in
a subject area, does that mean that
users spend more time in those books?

59. Page Views Per Session - ebrary
18.00
17.00
16.00
15.21
15.00
14.00
13.00
12.00
11.00
10.00
T
F
E Q R C G H D N
J M P B K
L U A S V Z

60. Page Views Per Session - EBL
24.00
22.00
20.00
18.90
18.00
16.00
14.00
12.00
10.00
F N T R M A E Q G C H D S B K P V
J
L
Z U

61. Average Rank Across Both
Aggregators: Page Views Per Session
1.
2.
3.
4.
5.
6.
7.
8.
F – History, Americas
T – Technology
R – Medicine
E – History, Americas
N – Fine Arts
Q – Science
C – Aux Sciences of History
G–
Geography, Anthropology, Re
creation
9. M – Music
10. H – Social Sciences
11. D – History, World, etc.
12. A – General Works
13. B – Philos, Psych, Religion
14. J – Political Science
15. P – Language & Literature
16. K – Law
17. S – Agriculture
18. L – Education
19. V – Naval Science
20. U – Military Science
21. Z – Bibliography and LIS

63. CONCLUSIONS

64. 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 (view, print, copy, download)
• Amount of use per session
– Does this measure amount of time spent?

65. Quality matters
• University press books used at a higher rate by
all measures
• Users appear to be making some judgment
about quality

66. 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
Highest # of page views by session
– L (Education)
•
•
•
•
High usage as % of available L titles
High average usage rate
Very strong performance relative to availability of L titles
Very low # of page views by session

67. How do we use these observations
to build better collections and
better serve our users?

68. For More Information…
• A white paper will be available on the ebrary
and EBL websites in March
• This presentation is available on SlideShare:
http://www.slideshare.net/MichaelLevineClark

69. Thank You
Michael Levine-Clark
Associate Dean for Scholarly Communication and
Collections Services
University of Denver Libraries
michael.levine-clark@du.edu