Wikis as Social Networks:Evolution and Dynamics

Ralf Klamma, Christian Haasler RWTH Aachen University SIG-KDD SNA Workshop, Henderson, NV August 24, 2008 Wikis as Social Networks: Evolution and Dynamics

Agenda

Motivation: MediaBases

WikiWatcher System Design

Wiki Evolution & Dynamics

Heterogeneity

Importance

Shortest Paths

Conclusions & Outlook

Agency & Patienthood in Digital Networks

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 Software

Wiki, Blog, Podcast, IM, Chat, Email, Newsgroup, Chat …

i*-Dependencies (Structural, Cross-media) Members ( Social Network Analysis : Centrality, Efficiency) Network of Artifacts Microcontent, Blog entry , Message, Burst, Thread, Comment, Conversation, Feedback (Rating) Network of Members Communities of practice Media Networks

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 www.prolearn-academy.org

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 XML dump/export files Parsing wiki data/ database transfer Measurement Network Analysis Generating Networks Visualization [[never exists]]

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

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

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

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

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

Conclusions & Outlook