3. What is social
network?
• Wikipedia definition-A social network is a social
structure made of individuals (or organizations)
called "nodes," which are tied (connected) by one or
more specific types of interdependency, such as
friendship, kinship, financial exchange, dislike or
relationships of beliefs, knowledge or prestige
• Social networking is the grouping of individuals into
specific groups, like small rural communities or a
neighborhood subdivision, if you will.
4. Social Networks
• Not a new concept, (6 degrees of separation)
• Ramsey theorem-At any party with at least six
people, there are three people who are all either
mutual acquaintances or mutual strangers
• People typically maintain 10-20 close relationships
among thousands of acquaintances
• Metcalf’s Law – value of a network increases n2
to #
of participants
– Not exactly, but in theory.
– Dependent upon interaction model
5. Online social
networking
• Social sites commonly used.
• Online community of internet users
• Common interests in hobbies, religion, or
politics.
• Socialize on sites by reading the profile
pages of other members and possibly even
contacting them.
6. Origin of social
sites
• Social network sites (SNSs) such as such as
Friendster, CyWorld, and MySpace allow individuals
to present themselves, articulate their social
networks, and establish or maintain connections
with others.
• These sites can be oriented towards work-related
contexts (e.g., LinkedIn.com), romantic relationship
initiation (the original goal of Friendster.com),
connecting those with shared interests such as
music or politics (e.g., MySpace.com), or the college
student population (the original incarnation of
Facebook.com).
7. Popular social
networking sites
• Personal sites-Myspace,orkut,Cyworld
• Professional/work related-LinkedIn
• Romantic relationship initiation-friendster
• Microblogging-Twitter
• Music-last.fm
• Movies-flickster
• Photos/pictures-flickr
8. Social Network
Analysis
We measure Social Network in terms of:
1. Degree Centrality: The number of direct connections a
node has. What really matters is where those
connections lead to and how they connect the
otherwise unconnected.
2. Betweenness Centrality: A node with high betweenness
has great influence over what flows in the network
indicating important links and single point of failure.
3. Closeness CentralityThe degree an individual is near
all other individuals in a network (directly or
indirectly). It reflects the ability to access
information through the network .
9. Why internet is
popular mean for
social networking
• The Internet is powerful because it bridges distance
at a low cost
• When people first meet online they tend to “like”
each other more
• Less stressful than face-to-face meeting
• Superficialities aside people focus on
communicating their “selves”
10. Social network
as a graph
• Nodes: A Unit That Possibly is Connected
• Individuals, Households, Workgroups ,
Organizations, States
• Relationships (A Specific Type of
Connection)
• A “Role Relationship”
• Gives Emotional Support
• Links Web Page
11. Social network
as a graph(conti.)
• Ties (Contain One or More Relationships)
• Friendship (with possibly many relationships)
• Affiliations (Person – Organization)
• Works for IBM; ACM Member; Football
Team
• One-Mode, Two-Mode Networks
12. An example of a social
Network diagram. The
node with the highest
Betweenness centrality
is marked in yellow.
13. A Network is
More Than The
Sum of Its Ties
• A Network Consists of One or More Nodes Could be
Persons, Organizations, Groups, Nations, Web Connected
by One or More Ties
• Could be One or More Relationships That Form Distinct,
Analyzable Patterns
• Can Study Patterns of Relationships OR Ties
• Emergent Properties
14. Types of social
networkers
• Alpha Socialisers – (a minority) people who
used sites in intense short bursts to flirt,meet
new people, and be entertained.
• Attention Seekers – (some) people who
craved attention and comments from
others,often by posting photos and
customising their profiles.
• Followers – (many) people who joined sites to
keep up with what their peers were doing.
15. Types of social
networkers(conti.)
Faithfuls – (many) people who typically used
social networking sites to rekindle old
friendships, often from school or university.
• Functionals – (a minority) people who tended
to be single-minded in using sites for a
particular purpose.
Source: Ofcom Social Networking Sites
research, September-October 2007
16.
17. Privacy concerns
• Social networking sites provide privacy options but
users are generally unaware or tend to ignore such
concerns
• Stalkers, terrorists, ill-doers, con-artists could
benefit from such issues
• Recent scandals-England :MI-6’s director’s wife
puts up photos of family on facebook.
• Facebook’s controversial decision to make visible
relationship actions to entire social group
