Semantic Social Network Analysis

Guillaume ERETEO

Social Network Analysis?

• A science to understand the structure, the interactions and the strategic positions in social networks.

• Sociograms[Moreno, 1933]

• What for? – To control information flow– To improve/stimulate communication– To improve network resilience– To trust

[Wasserman & Faust 1994] [Scott 2000] [Mika 2007]

Community detection

Influences the wayinformation is shared[Coleman 1988]

Influences the way actors behave[Burt 2000]

• Global structure• Distribution of actors

and activities

Centrality: strategic positions

Degree centrality: Local attention

beetweenness centrality:reveal broker "A place for good ideas"[Burt 1992] [Burt 2004]

Closeness centrality: Capacity to communicate

[Freeman 1979]

Critical mass

Balance Theory[Heider 1958]

Computer networks as social networks

[Wellman 2001]

web 2.0 amplifies Network effect !

Semantic social networks

http://sioc-project.org/node/158

Millions of FOAF profiles online

Social tagging

SCOT

SNA on the semantic web

Rich graph representations reduced to simpleuntyped graphs in order to apply SNA

[Paolillo and Wright 2006]

Foaf:knows

Foaf:interest

The Semantic SNA Stack

SemSNA an ontology of SNA

Parametrized n-Degree

constructconstruct{?y semsna:hasInDegreesemsna:hasInDegree _:bO _:bO semsna:isDefinedForPropertysemsna:isDefinedForProperty param[type] _:bO semsna:hasValuesemsna:hasValue ?indegree_:b0 semsna:hasDistance param[length]param[length]

}select ?y count(?x) as ?indegree{

?x $path$path ?yfilter(match($path, star(star(param[type]param[type]))))fitler(pathLength($path) <= pathLength($path) <= param[length]param[length])

}group by ?y

Most popular manager in a work subnetworks

select ?y ?indegree{

?y rdf:type domain:Manager

?y semsna:hasInDegreesemsna:hasInDegree ?z

?z semsna:isDefinedForProperty semsna:isDefinedForProperty rel:worksWithrel:worksWith

?z semsna:hasValuesemsna:hasValue ?indegree

?z semsna:hasDistancesemsna:hasDistance 2

}

order by desc(?indegree)

PREFIX foaf: <http://xmlns.com/foaf/0.1/> select ?from ?to ?between $path pathLength($path) as ?

length where{?from $path ?tograph $path{?between param[type]param[type] ?j}filter(match($path, star(param[type]param[type]), 'sa')) optional { ?from param[type]param[type]::?p ?to }filter(!bound(?p))

filter(?from != ?between)filter(?between != ?to)

}group by $path order by ?length

Parametrized Shortest paths for betweenness

gb<type>(from, to)

PREFIX foaf: <http://xmlns.com/foaf/0.1/> PREFIX semsna: <http://ns.inria.fr/semsna/2008/10/13/voc>add{

?x semsna:isMemberOf ?uri}select ?x ?y genURI(<myorg>) as ?uri from Gwhere { ?x $path ?y filter(match($path, star(param[type]param[type]), 'sa'))}group by any

Parametrized ComponentCb<type>(G)

Current Community detection algorithms

• Hierarchical algorithms

– Agglomerative (based on vertex proximity):• [Donetti and Munoz 2004] [Zhou Lipowsky, R. 2004]

– Divisive (mostly based on centrality):• [Girvan and Newman 2002] [Radicchi et al 2004]

• Based on heuristic (modularity, randon walk, etc.)

• [Newman 2004], [Pons and Latapy 2005], [Wu and Huberman 2004]

TowardSemantic CommunityDetection

likes

ingredient

typemainDish

Food

subclassOf

type

SemSNA an ontology of SNA

[Conein 2004][Wenger 1998]

#Guigui

#bk81

#tag27

#bk34

#tag92

#Fabien

Semantic web

Web sémantique

hasTaghasTag

hasBookmark hasBookmark

ShareInterest

MentorOf

label

label

#MichelMentorOf Collaborate

nameGuillaume Erétéo

organization

guillaume.ereteo@orange-ftgoup.com

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