INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Linked – But how?
Bettina Hoser, Cora Schaefer
School of Economics
Institute for Information Engineering and Management
Schroff-Chair for Information Services and Electronic Markets
Universität Karlsruhe (TH)
Germany
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Research Question
Does link and vertex definition on a
social website influence
social network analysis results?
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Outline
• Social Sites
– Types and objectives of social sites
• Vertex and Link definition
– Technology and incentives problems
• Possible Influence:
– Guest accounts, friendsters and time decay
• Conclusion
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Social Sites: Types
• Community
– Topic oriented: bibsonomy
– No specific topic: MySpace, Facebook
– Target group oriented: Flickr, YouTube
• Commercial oriented
– Amazon.com
– SecondLife?
• Others
– Mixture: StudiVZ, Xing, Tremor
– ???
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Social Sites: Objectives
•
Community support
– Platform for like-minded users
– Platform for Help (9/11, Kathrina)
– Dating
– …
•
Commercial leverage
– Business models based on ‚normal user‘ and ‚Premium users‘
– Advertisement
– Recommendation networks (Tremor)
– …
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Vertices and Links
•
Assumptions:
– Vertices
• individual persons
• Only one vertex per person
– Link
• Exists between two actors according to intended definition
• Is kept up to date by actor
– Time
• Evolution vs revolution
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Vertices and Links: Technology
•
Technology of the site defines
– What a vertex can be:
• individual
• group
• ???
– Link definition:
• Friendship,
• Acquaintance,
• Business relation
• ???
– Normally time constraints are not made (but are being thought about in
exchange sites)
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Vertices and Links: Incetive compatibility
What drives actors to
form,
maintain, or
eliminate
links?
→ Game theory: utility?
And what can make actors form the kinds of links the social site provider
wants them to form?
→ Not yet solved.
Incentive problem!
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Influences on structure: Guest accounts etc
•
Example: 7 internet boards at the Universtity of Konstanz, Germany
•
User classes:
– registered user with know online identity
– Non-registered user → guest account
– registered user, who still uses the guest account
•
Results:
– To eliminate the guest account from the analysis can, but does not need to
have a strong impact on the network structure found!
– This depends on the characteristics of the board analyzed. (centralization)
– To ignore the guest account, one has to make sure that the strucuture is not
disturbed.
•
Incentive problem: in some boards the use of the guest account is not tolerated, but
technically possible. In other boards the use is tolerated.
•
Collaboration with Cora Schaefer
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Influences on structure: link semantics
•
Other examples:
– ‚I am your friendster, not your friend‘
– Links from the USNavy Profile within MySpace
– Different link ‚kinds‘ in Xing
– Controversy or just discussion (Wikipedia)
•
Cultural differences
– American ‚friends‘ and european ‚friends‘ (Circle of Cool, MTV)
•
Economic reasons
– Links on Tremor.com
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Influences on structure: time decay
•
•
•
Blog roll problem
Xing: problem of up to date friend list
Event driven: news, marketing
•
Open topic: model for time decay (churn rate?) of links and actors.
ECCS 2007, Dresden
INFORMATIONSDIENSTE UND ELEKTRONISCHE MÄRKTE
Conclusion
•
Large data sets have become available (MySpace, SecondLife,
Wikipedia), and computer capacity and algorithms have made analysis
possible.
•
Social network analysis has become more and more an interdisciplinary
research area, and – at the moment – a hype.
•
Care should be taken when analyzing social sites to also take the social,
psychological and economical view into account. It may alter the
interpretation.
• Just because it‘s possible, does not mean it‘s meaningful.
ECCS 2007, Dresden