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The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics Socio-semantic dynamics in a blog network Jean-Philippe Cointet CREA (CNRS/EP, France) AND Camille Roth CAMS (CNRS/EHESS, France) IEEE SOCIALCOM09, VANCOUVER, BC – AUG 29–31, 2009

Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

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Page 1: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Socio-semantic dynamics in a blog network

Jean-Philippe CointetCREA (CNRS/EP, France)

AND

Camille RothCAMS (CNRS/EHESS, France)

IEEE SOCIALCOM09, VANCOUVER, BC – AUG 29–31, 2009

Page 2: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

A SOCIAL network

Three kinds of links for each blog...

citation: post citation links

interaction: comment links

affiliation: blogroll links

...where contents circulate

in terms of topics (W)

in terms of cultural items (U)

Dataset: US blogosphere

scope: 4 months of ’08 campaign

network: citations

nodes: 1, 066 blogs (RTGI)

citation link

blogroll linkcomment link

Page 3: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

A socio-SEMANTIC network

Three kinds of links for each blog...

citation: post citation links

interaction: comment links

affiliation: blogroll links

...where contents circulate

in terms of topics (W)

in terms of cultural items (U)

Dataset: US blogosphere

scope: 4 months of ’08 campaign

network: citations

nodes: 1, 066 blogs (RTGI)

semantic characterization

“relevant” syntagms(“health insurance”, “climate change”, “national

security”, “super Tuesday”, “human rights”...)

urls: “www.youtube.com/x1hqwkeac”, etc.

Page 4: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

A DYNAMIC socio-semantic network

Three kinds of links for each blog...

citation: post citation links

interaction: comment links

affiliation: blogroll links

...where contents circulate

in terms of topics (W)

in terms of cultural items (U)

Dataset: US blogosphere

scope: 4 months of ’08 campaign

network: citations

nodes: 1, 066 blogs (RTGI)

http://presidentialwatch08.com/

Page 5: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Socio-semantic configuration

Jan 1 Michigan Primary Super Tuesday feb 170

0.01

0.02

0.03

0.04

0.05

0.06

time

freq

uen

cyof

term

s

super tuesdaymichigancaliforniahuckabee

d

c

ba

19/02

20/02

20/02

26/02

Page 6: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Socio-semantic configuration

semantic profile of a blog i :

Wi (w) :=Wi (w)P|W|

w=1 Wi (w)

· log|B|

|{j, Wj (w) > 0}|

semantic distance

between blogs i and j :

δ(i , j) = 1− Wi · Wj

‖Wi‖‖Wj‖

[0;.1[ [.1;.2[ [.2;.3[ [.3;.4[ [.4;.5[ [.5;.6[ [.6;.7[ [.7;.8[ [.8;.9[ [.9;1]0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

P(δ

)

δ

Semantic distance distributions. Triangles: computed over thewhole set of possible blog pairs. Crosses: distribution computed onlinked blogs.

Page 7: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Computing link creation propensity

→ estimate the “propensity of interaction”...that it is more or less likely for a node (ora dyad) with property “m” to receive a link...which may be simply estimated by:

f (m) =ν(m)

N(m)

0 50 100 150 200

100

101

k

f(k

)

ν(m) = number of links pointing towards an agent of type m(resp. number of new dyads of type m) during a time period,

N(m) = number of agents (resp. of dyads) of type m.

Page 8: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Computing link creation propensity

→ estimate the “propensity of interaction”...that it is more or less likely for a node (ora dyad) with property “m” to receive a link...which may be simply estimated by:

f (m) =ν(m)

N(m)0 50 100 150 200

100

101

k

f(k

)

ν(m) = number of links pointing towards an agent of type m(resp. number of new dyads of type m) during a time period,

N(m) = number of agents (resp. of dyads) of type m.

Page 9: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Dynamics of the social network

in-degree effects

→ increasing, plateauing

topological distance effects

→ strong trend to repetition and localinteraction

semantic distance→ strong trend to homophily

primarily “social”?

social distance and degree

0 50 100 150 200

100

101

k

f(k

)

Page 10: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Dynamics of the social network

in-degree effects

→ increasing, plateauing

topological distance effects

→ strong trend to repetition and localinteraction

semantic distance→ strong trend to homophily

primarily “social”?

social distance and degree

1 2 3 4 >410

−2

10−1

100

101

102

d

ˆf(d

)

Page 11: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Dynamics of the social network

in-degree effects

→ increasing, plateauing

topological distance effects

→ strong trend to repetition and localinteraction

semantic distance→ strong trend to homophily

primarily “social”?

social distance and degree

[0;.1] ].1;.2] ].2;.3] ].3;.4] ].4;.5] ].5;.6] ].6;.7] ].7;.8] ].8;.9] ].9;1]10

−1

100

101

102

δ

ˆg(δ

)

Page 12: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Dynamics of the social network

in-degree effects

→ increasing, plateauing

topological distance effects

→ strong trend to repetition and localinteraction

semantic distance→ strong trend to homophily

primarily “social”?

social distance and degree

1 2 3 >3 [0;0.2[ [0.2;0.4[ [0.4;0.6[ [0.6;0.8[ [0.8;1]

10−4

10−3

10−2

10−1

100

semantic distance δsocial distance d

prop

ensi

onp(d

,δ)

Page 13: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Dynamics of the social network

in-degree effects

→ increasing, plateauing

topological distance effects

→ strong trend to repetition and localinteraction

semantic distance→ strong trend to homophily

primarily “social”?

social distance and degree

12

3>3 0

50100

10−2

10−1

100

101

102

social capital ksocial distance d

prop

ensi

onp(d

,k)

Page 14: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Information flows: measures on the post network

Dyadic measures:

raw, weighted network,aggregated on 4 months

attentional matrix a...→ and total attentionαa = 5/6

detachment matrix

“edge range”:

quantifying shortcuts d

b

c

a

1

3 2

2

13

f

e3

2

2

1

1

1

1

Page 15: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Information flows: measures on the post network

Dyadic measures:

raw, weighted network,aggregated on 4 months

attentional matrix a...→ and total attentionαa = 5/6

detachment matrix

“edge range”:

quantifying shortcuts d

b

c

a

1/6

3/4 2/3

2/6

1/53/6f

e3/5

2/3

2/2

1/3

1/4

1/3

1/5

Page 16: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Information flows: measures on the post network

Dyadic measures:

raw, weighted network,aggregated on 4 months

attentional matrix a...→ and total attentionαa = 5/6

detachment matrix

“edge range”:

quantifying shortcuts d

b

c

a

6

4/3 3/2

3

52f

e5/3

3/2

1

3

4

3

5

Page 17: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Information flows: measures on the post network

Dyadic measures:

raw, weighted network,aggregated on 4 months

attentional matrix a...→ and total attentionαa = 5/6

detachment matrix

“edge range”:

quantifying shortcuts

d

b

c

a

6

4/3 3/2

5

2

f

e

5/3

3/2

1

3

4

3

5

Page 18: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Information cascade

d

c

ba

19/02

20/02

20/02

26/02

An example of diffusion subgraph, acommon “resource” and a set ofcitation links between blogs

Diffusion subgraphs

100

101

102

100

101

102

103

104

size of diffusion subgraphs

num

ber

ofdi

ffus

ion

subg

raph

s

linksnodes

⇒ heterogeneous cascade sizes

Page 19: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

An ego-centered perspective

d

c

ba

19/02

20/02

20/02

26/02

We focus on the total number of“transmissions” generated by blogswith a given total attention α

a bit more “global”...

d

c

ba

19/02

20/02

20/02

26/02

second transmissions: we focus on“later transmissions”, i.e. after a firsttransmission event

role of the total attention on thenumber of diffusion links

10−2

10−1

100

101

102

10−1

100

101

102

Total Attention αN

umber

oftr

anm

issi

ons

Larger active readership => largernumber of diffusion links, yet not linearly

Page 20: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

An ego-centered perspective

d

c

ba

19/02

20/02

20/02

26/02

We focus on the total number of“transmissions” generated by blogswith a given total attention α

a bit more “global”...

d

c

ba

19/02

20/02

20/02

26/02

second transmissions: we focus on“later transmissions”, i.e. after a firsttransmission event

role of the total attention on thenumber of diffusion links

10−2

10−1

100

101

102

10−1

100

101

102

Total Attention αN

umber

oftr

anm

issi

ons

Larger active readership => largernumber of diffusion links, yet not linearly

Page 21: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

A more global perspective

→ role of edge-range on thenumber of grand-children

We focus again on transmissions occurringafter a first transmission event

d

c

ba

19/02

20/02

20/02

26/02

0 10 20 30 40 50 60 70 80 90 1000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

edge range rM

ean

num

ber

of2n

dtr

ansm

issi

ons

An information which has been transmitted through a “median” linkgenerates a larger number of grandchildren

Page 22: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Concluding remarks

Co-evolution of content and relationshipsPatterns not necessarily linked to authority onlyPatterns not necessarily ego-centered only→ divergent from the “neighbor-based-influence” perspective

Thank [email protected] & [email protected]

Page 23: Socio-semantic dynamics in a blog networkcamille.roth.free.fr/travaux/cointet-roth--ieeesocialcom09-slides.pdf · affiliation: blogroll links...where contents circulate in terms

The “blogosphere” as a socio-semantic network Link creation dynamics Diffusion dynamics

Concluding remarks

Co-evolution of content and relationshipsPatterns not necessarily linked to authority onlyPatterns not necessarily ego-centered only→ divergent from the “neighbor-based-influence” perspective

Thank [email protected] & [email protected]