CSCW2012 submission - see http://katrina.is for more information about my work and the paper this work is from.

1. Tie Strength
in Question & Answer
on Social Network Sites
Katrina Panovich @katrina_
with Rob Miller & David Karger
MIT CSAIL
1
Wednesday, February 15, 12 1

2. what song was in this
commercial?
2
Wednesday, February 15, 12 2

3. 3
Wednesday, February 15, 12 3

4. 4
Wednesday, February 15, 12 4

5. 5
Wednesday, February 15, 12 5

6. I want to switch to linux full time but
need a better music player. Any leads
on one that can handle upwards of
500gb of files?
6
Wednesday, February 15, 12 6

7. related work
social q&a raban and harper 2008
harper, raban, rafaeli, konstan 2008
ackerman and palen 1996
social search evans and chi 2008
pirolli 2009
social networks
lampe and ellison 2008
7
Wednesday, February 15, 12 7

8. 50.6% had used their
status message to ask
a question of their
social network before
Morris, M. R., Teevan, J., Panovich, K.
What Do People Ask Their Social Networks, and Why?
CHI 2010.
8
Wednesday, February 15, 12 8

9. 29% Recommendation 29% Technology
recommendation technology
entertainment
opnion
home & family
factual knowledge
professional
rhetorical places
invitation restaurants
current events
favor
shopping
social connection
ethics and philosopy
offer
Morris, M. R., Teevan, J., Panovich, K.
What Do People Ask Their Social Networks, and Why?
CHI 2010.
9
Wednesday, February 15, 12 9

10. How well do you
know this person?
Median 4 out of 5
Morris, M. R., Teevan, J., Panovich, K.
A Comparison of Information Seeking Using
Search Engines and Social Networks.
ICWSM 2010.
10
Wednesday, February 15, 12 10

11. 11
Wednesday, February 15, 12 11

12. tie strength:
measure of the strength of a friendship
12
Wednesday, February 15, 12 12

13. The Strength of
Weak Ties
weak ties travel in
different circles & know
more diverse information
Granovetter, M. American Journal of Sociology,
May 1973.
13
Wednesday, February 15, 12 13

14. The Strength of
Weak Ties
weak ties travel in
different circles & know
more diverse information
Granovetter, M. American Journal of Sociology,
May 1973.
14
Wednesday, February 15, 12 14

15. weak ties...
- cited at least 19,302 times
- can help us get jobs
- provide us with bridging social capital
- know diverse information
- are our extended community
- can introduce serendipity
15
Wednesday, February 15, 12 15

16. research questions
16
Wednesday, February 15, 12 16

17. research question 1
Does tie strength have
the same ‘strength of
weak ties’ effect in this
case?
17
Wednesday, February 15, 12 17

18. research question 2
How does the relation
between tie strength
and answer quality
play out?
18
Wednesday, February 15, 12 18

19. study overview
- participants asked questions
- we surveyed them about the responses
they got
- regression analysis of tie strength vs
answer qualities
19
Wednesday, February 15, 12 19

20. strong ties...
provide answers we value
more in general
provide already-known
information less
contribute to overall
knowledge more
20
Wednesday, February 15, 12 20

21. methodology
21
Wednesday, February 15, 12 21

22. ?
participants asked tech
recommendation questions
22
Wednesday, February 15, 12 22

23. ?
23
Wednesday, February 15, 12 23

24. 19 participants
?
24
Wednesday, February 15, 12 24

25. does anyone have a
good camera to
recommend? size-wise,
i'm looking for
something between a
giant DSLR and a tiny
point-and-shoot
25
Wednesday, February 15, 12 25

26. anyone flown delta?
good? bad?
26
Wednesday, February 15, 12 26

27. 19 participants
104 responses
all answered
median 3 responses
27
Wednesday, February 15, 12 27

28. 28
Wednesday, February 15, 12 28

29. how close each friendship was
29
Wednesday, February 15, 12 29

30. Gilbert & Karahalios CHI ’09
Predicting Tie Strength with Social Media
Days since last comm
Participant-init wall posts
Days since first comm
Inbox thread depth
Intimacy x Structural
Participant’s no. of friends
Wall words exchanged
Inbox pos. emotion words
Mean ts of mutual friends
Social Distance x Structural
Educational difference
Participant’s no. of apps
Structural x Structural
Wall intimacy words
Reciprocal Serv. x Reciprocal
30
Wednesday, February 15, 12 30

31. Days since last comm
Participant-init wall posts
Days since first comm
Inbox thread depth
Intimacy x Structural
Participant’s no. of friends
Wall words exchanged
Inbox pos. emotion words
Mean ts of mutual friends
Social Distance x Structural
Educational difference
Participant’s no. of apps
Structural x Structural
Wall intimacy words
Reciprocal Serv. x Reciprocal
31
Wednesday, February 15, 12 31

32. Days since last communication
Days since first communication
Wall words exchanged
Mean tie strength of mutual friends
Participant’s number of friends
Inbox positive emotion words
Wall intimacy words
32
Wednesday, February 15, 12 32

33. How strong is your relationship with this person?
r = 0.50
33
Wednesday, February 15, 12 33

34. tie strengths of
all friends of all participants
2500
Frequency
2000
1500
1000
500
0
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
34
Wednesday, February 15, 12 34

35. tie strengths of
friends who answered questions
30
25
Frequency
20
15
10
5
0
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
35
Wednesday, February 15, 12 35

36. 30
2500
25
Frequency
Frequency
2000
20
1500
15
1000
10
500
5
0
0
0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength Tie Strength
all friends all answerers
36
Wednesday, February 15, 12 36

37. answer quality
37
Wednesday, February 15, 12 37

38. unpacking answer quality
1. content
2. novelty of the information
3. person
38
Wednesday, February 15, 12 38

39. unpacking answer quality
1. content
2. novelty of the information
3. person
content
39
Wednesday, February 15, 12 39

40. unpacking answer quality
1. content
2. novelty of the information
3. person
novelty
40
Wednesday, February 15, 12 40

41. unpacking answer quality
1. content
2. novelty of the information
3. person
person
41
Wednesday, February 15, 12 41

42. how on topic is this answer?
content
42
Wednesday, February 15, 12 42

43. how supportive is this answer?
content
43
Wednesday, February 15, 12 43

44. how interesting is this answer?
content
Wednesday, February 15, 12 44

45. how much do you trust
this answer?
content
45
Wednesday, February 15, 12 45

46. how much does this answer
provide novel information?
novelty
Wednesday, February 15, 12 46

47. how much does this answer verify
information you already knew?
novelty
47
Wednesday, February 15, 12 47

48. how much does this answer
contribute to your
overall knowledge?
novelty
48
Wednesday, February 15, 12 48

49. how knowledgeable is
this person about this topic?
person
49
Wednesday, February 15, 12 49

50. what value do you generally place
on answers from this person?
person
50
Wednesday, February 15, 12 50

51. tie strength
vs
answer quality
linear regression results
51
Wednesday, February 15, 12 51

52. Overall Already Value
Wednesday, February 15, 12
Knowledgeable Novel Trust
52
Topic Interesting Supportive
52

53. what value do you
generally place on answers
Value
from this person?
how much does this
answer verify information
Already
you already knew?
how much does this
answer contribute to
Overall
your overall knowledge?
53
Wednesday, February 15, 12 53

54. tie strength and value of
this friend’s answers Tie Strength and Value
7
6
R2 = 0.065
5
β = 0.071
Value
p < 0.05
4
3
2
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
What value do you generally place on answers from this person?
54
Wednesday, February 15, 12 54

55. tie strength and value of
this friend’s answers Tie Strength and Value
7
6
R2 = 0.065
5
β = 0.071
Value
p < 0.05
4
Closer friends provide answers we
3
value more in general.
2
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
What value do you generally place on answers from this person?
55
Wednesday, February 15, 12 55

56. tie strength and
already known information Tie Strength and Already Known Information
7
6
R2 = 0.062
5
Knew Already
β = –0.038
4
p < 0.01
3
2
1
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
How much does this answer verify information you already knew?
56
Wednesday, February 15, 12 56

57. tie strength and
already known information Tie Strength and Already Known Information
7
6
R2 = 0.062
5
Knew Already
β = –0.038
4
p < 0.01
3
Closer friends were less likely to provide information
2
that the participant already knew.
1
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
How much does this answer verify information you already knew?
57
Wednesday, February 15, 12 57

58. tie strength and
overall knowledge
Tie Strength and Overall Knowledge
7
6
R2 = 0.036
5
Overall Knowledge
β = 0.031
4
p < 0.05
3
2
1
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
How much does this answer contribute to your overall knowledge?
58
Wednesday, February 15, 12 58

59. tie strength and
overall knowledge
Tie Strength and Overall Knowledge
7
6
R2 = 0.036
5
Overall Knowledge
β = 0.031
4
p < 0.05
3
Closer friends’ answers that are more likely to
2
contribute to our overall knowledge.
1
0.0 0.2 0.4 0.6 0.8 1.0
Tie Strength
How much does this answer contribute to your overall knowledge?
59
Wednesday, February 15, 12 59

60. correlations between
quality metrics
60
Wednesday, February 15, 12 60

61. How on topic was this answer?
How knowledgeable is this person
β = 0.51
about this topic?
0.60 How supportive is this answer?
How much do you trust this
0.48 answer?
61
Wednesday, February 15, 12 61

62. How knowledgeable/trustworthy is
this friend about this topic?
0.35 How on topic is this answer?
What value do you generally place
0.44 on answers from this person?
0.43 How supportive is this answer?
62
Wednesday, February 15, 12 62

63. tie strength
expertise
63
Wednesday, February 15, 12 63

64. tie strength
expertise
64
Wednesday, February 15, 12 64

65. I look for answers
where people didn’t just
recommend a product
but gave reasons from
their experience or
pointed to reviews
online.
65
Wednesday, February 15, 12 65

66. I guess a lot of
evaluating is my
estimation of the source
reliability (the person).
66
Wednesday, February 15, 12 66

67. [It’s] just kind of a
personal experience
with products that I’m
looking for.
...
67
Wednesday, February 15, 12 67

68. For example, I know
[0.06] does a lot of
camera work, and
[0.718] is a professional
photographer, so I
value their answers
more.
68
Wednesday, February 15, 12 68

69. here’s where tie strength matters
value overall knowledge already known info
and here’s where it doesn’t.
on topic knowledgeable about topic supportive
interesting novel information trust
69
Wednesday, February 15, 12 69

70. implications
70
Wednesday, February 15, 12 70

71. Horowitz, D., Kamvar, S. The anatomy of a large-scale social search engine. WWW 2010.
71
Wednesday, February 15, 12 71

72. Horowitz, D., Kamvar, S. The anatomy of a large-scale social search engine. WWW 2010.
72
Wednesday, February 15, 12 72

73. Horowitz, D., Kamvar, S. The anatomy of a large-scale social search engine. WWW 2010.
73
Wednesday, February 15, 12 73

74. limitations
74
Wednesday, February 15, 12 74

75. 75
Wednesday, February 15, 12 75

76. 76
Wednesday, February 15, 12 76

77. Does tie strength have the
same ‘strength of weak
ties’ effect in this case?
How does the relation
between tie strength and
answer quality play out?
77
Wednesday, February 15, 12 77

78. when they
mattered at all,
stronger ties
were actually
slightly better
78
Wednesday, February 15, 12 78

79. tie strength
expertise
79
Wednesday, February 15, 12 79

80. thank you
Greg Vargas,
Karrie Karahalios, Mark Ackerman
UID and Haystack groups
our participants
Xerox, NSF, Google
reviewers
80
Wednesday, February 15, 12 80

81. Tie Strength
Value
in Question & Answer
on Social Network
Sites
Already
strong ties > weak ties
expertise > tie strength
Overall
Katrina Panovich MIT CSAIL
http://katrina.is
81
Wednesday, February 15, 12 81