&quot;Il semble que le terme « masse critique » vienne d&apos;une observation du trafic routier en Chine, où sans feux de signalisation aux croisements, les cyclistes attendent d&apos;être assez nombreux, de faire masse pour s&apos;engager et traverser ensemble. &quot; Le principe de masse critique dans un réseau social correspond à un niveau d&apos;activité à partir duquel le réseau change d&apos;état de manière permanente. Par exemple, à partir d&apos;un certain nombre de personne et d&apos;un volume d&apos;activité minimale d&apos;interaction, un groupe de personne devient une communauté d&apos;intérêt.
Community detection helps understanding the global structure of a network and the distribution of actors and activities. Moreover, the community structure influences the way information is shared and the way actors behave. Information spread quickly in a community and is shared by most of it members.
The centrality highlights the most important actors of the network and three definitions have been proposed by Freeman. The degree centrality considers nodes with the higher degrees (number of adjacent edges). The closeness centrality is based on the average length of the paths linking a node to others and reveals the capacity of a node to be reached. The betweenness centrality focuses on the capacity of a node to be an intermediary between any two other nodes. A network is highly dependent on actors with high betweenness centrality due to their position as intermediaries and brokers in information flow.
Corporate social networks - world usability day
corporate social networks
Guillaume ERETEO – world usability day
"The Intranet tends to follow trends
from the web, and social networking is
[Nielsen Norman Group 2009]
"It's better to structure information
according to how people use it, rather
than what department owns it"
[Jakob Nielsen 2009]
"the use of emergent social software platforms
within companies, or between companies and
their partners or customers" [Mc Afee 2006]
"emergent social software platforms"
"digital environments in which contributions and
• "globally visible and persistent over time"
• performed with social softwares that "enable people
to rendezvous, connect or collaborate through
computer-mediated communication and to form
• emergent, freeform, with "patterns and structure
inherent in people’s interactions".
[Mc Afee 2009]
intranet of people
Links follow me @ereteog
Authoring "read write web"
Extension see also
A social network is made of actors (people,
organizations, group) that are tied by social links.
• explicit and declared relations
• interactions between actors
• affiliation between actors
the bull's eye of @amcafee
• Strong links: close
• Weak links professional
• Potential links:
• Absent relationships:
remainder of the
"resources embedded in one's social networks,
resources that can be accessed or mobilized
through ties in the networks" [Lin 2008]
enterprise 2.0 and corporate social
Wiki, online office suites:
social networking service:
• link maintenance
• non-redundant information
• network bridging
blog, social tagging:
• efficient search
• link formation
• collective intelligence
Influences the way
information is shared
influences the way actors
behave [Burt 2000]
distribution of actors and activities
Centrality: strategic positions
"A place for good ideas"
[Burt 1992] [Burt 2004]
transitivity of relationships
evaluating social opportunities
Analyzing intranet of people
sound great! but… what for?
maintain strong links
• exploit the semantic of links to filter
• highlight influent actors and popular
resources not yet mobilized
strengthen weak links
highlight valuable weak links that provide access
to relevant assets and opportunities
filter potential social capital and
connect communities and people
that should collaborate
Open problem: using analysis metrics
to leverage social intranet usability