Wikis as Social Networks:Evolution and Dynamics

Lehrstuhl Informatik V(Informationssysteme)

Prof. Dr. M. JarkeI5-RK-0808-1

CUELC

Ralf Klamma, Christian Haasler

RWTH Aachen University

SIG-KDD SNA Workshop, Henderson, NV

August 24, 2008

Wikis as Social Networks:Evolution and Dynamics



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Agenda

Motivation: MediaBases WikiWatcher System Design Wiki Evolution &

Dynamics– Heterogeneity– Importance– Shortest Paths

Conclusions & Outlook

Agency & Patienthood in Digital Networks

Agency & Patienthood in Digital Networks



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Motivation:Cross-Media Dynamic Network Analysis

Interdisciplinary multidimensional model of digital networks– Dynamic network analysis (DNA) is defining measures for evolving

social relations– Actor network theory (ANT) is connecting human and media agents– i* framework is defining changing strategic goals and dependencies – Theory of media transcriptions is studying cross-media knowledge

Social SoftwareWiki, Blog, Podcast, IM, Chat, Email, Newsgroup, Chat …

i*-Dependencies(Structural, Cross-media)

Members(Social Network Analysis: Centrality,

Efficiency)

Network of ArtifactsMicrocontent, Blog entry, Message, Burst, Thread,

Comment, Conversation, Feedback (Rating)

Network of Members

Communities of practice

Media Networks



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Motivation:MediaBases

Collection of Social Software artifacts with parameterized PERL scripts– Mailing lists– Wikis– Blogs– Many more

Database support by IBM DB2, eXist, Oracle, ...

Web Interface based on Plone/Zope, LAS, ...

Strategies of visualization– Tree maps– Cross-media graphs

Klamma et al.: Pattern-Based Cross Media Social Network Analysis for Technology Enhanced Learning in Europe, EC-TEL 2006



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WikiWatcher – System Design

article

Article pages,URLS,

Revisions

Tim

Liz

Joe

123.45.67.89

Authors

RDB

Stage 1: SAX-based Parser in PERL

Stage 2: Dynamic Analysis and Visualization

Wiki Network Data

Metadata

[[Article]]

[[requested]]

article

[http://…]

[[Article2]]

Generating XMLdump/export files

Parsing wiki data/database transfer

Measurement

Network Analysis

Generating Networks

Visualization

[[never exists]]



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Network Heterogeneity

Author Networks– Author nodes

(anonymous/registered users)– Edges represent collaboration

between authors during a period t

Article Networks– Article nodes

(incl. wiki namespaces)– Directed edges (links)

between articles As expected both kind of

networks stay heterogenous



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Importance of Network Actors

Articles: High betweenness centrality controls the flow of information within a Wiki

Betweenness values grow up or stay nearly constant during the evolution process

Determines– Important actors– Important articles– Vandalism



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Evolution of Shortest Paths

Densification Power Law: Complex networks may become denser during their growth

Generally this could not verified for wiki author networks!

The average distances stagnate at nearly 2 for all considered author networks



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Evolution of Author Networks Strongly connected components merged by collaboration of

two wiki authors

Author Network of German Wikia in July 2007 Author Network of German Wikia in August 2007



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Some more Hypotheses in the Study

Hypotheses (Author Networks) Result

Weakening of the new author rate Approved only in some Wikis

Quick creation of author communities around articles Approved

Authorial leadership [Reagle07] Approved

Anonymous vs. registered author rate Approved only in some Wikis

Registered authors connect anonymous authors Approved only in some Wikis

Hypotheses (Article Networks) Result

Weakening of new article rate Approved only in some Wikis

Correlation between article size and #revisions Approved

Weakening of article size growth Approved

Correlation between article size and #discussions Approved only in some Wikis

clustering coefficient of article nodes densifies Approved



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Conclusions & Outlook

WikiWatcher as part of an integrated MediaBase approach

Dynamic Social Network Analysis applicable for Wiki Networks (independent of Wiki Engines)– Heterogeneous Author Collaboration & Article Networks– Dynamic Centrality Measures for Wiki Actors– Evolution of Shortest Paths in Wikis

Outlook– Cross-Media Integration– Explicit Strategic Modeling for Wiki Communities

Wikis as Social Networks:Evolution and Dynamics

Technology

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