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Why Networks?

Dimitrina Dimitrova, Ph.D.

Guest lecture

Humber College

October 22, 2009

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Oultine

– What are social networks?– Why are networks important?– How do we study them? – Some key ideas from SNA– How can we use these ideas?

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Why Social Networks?

– People are always connected to others

Aristotle: “social animals”

– Relationships and networks affect our lives

– Recent attention Both our knowledge about

and the role of networks have increased

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What Are Social Networks?

K. Stephenson http://www.drkaren.us/KS_video01.htm

Definition: “Set of actors with their ties” Actor/ node: people, organizations,

groups, or any unit that is connected to others

Ties, Relationships: connectionsSociogram

Many types of ties / networksGive advice, collaborate, visit

Relationships do not arise randomly

Study networks Connections are not evenly

distributed

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Why Are Networks Important?

Networks affect Behaviour Process such as information flows, influence Outcomes such as promotions, performance

Organizational networks Informal ties, through which work gets (or does not) get

done.Some networks: leaders, executives, work groups, connections

between departments/organizations Increasingly important

Information flows in traditional organizations versus information flows along informal networks

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How do We Study Social Networks?

Social Network Analysis: a perspective that studies social relations, viewed in terms of nodes and ties. Captures patterns of relationships among actors Explanations based on position in the network and its

structure Constraints and opportunities

Steps1) Collect information: Social network survey

2) Analyze information: UCINET

3) Take action: networking activities, etc.

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Data matrix, Moreno

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Sociogram, Moreno

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How does This Work?

Paul

Outgoing ties

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Paul

All ties

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How does SNA Describe Networks?

Origin • Homophily (similarity) “Birds of a feather flock together”• Transitivity (transfer)

Relationships • Weak (E.g. acquaintances) versus strong (E.g. friends) ties• Directed and undirected ties, reciprocal versus non-

reciprocal ties

Position • Isolates (no ties), pendants (one tie), stars (many ties),

bridges (connectors)

Structure: • Connectivity, internal groupings, disconnects/structural holes

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Organizational Network

Adapted from Cross& ParkerPositions: isolate, pendant, central actors, bridgeInformation flows: long paths, vulnerability, possible bottleneck

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York University class •Tie: “Know”•Average number of ties 1.8•Range from 0 to 4

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Humber College class, Section 2 Tie: “Talk to regularly” Average number of ties 8.6 Range from 3 to 15

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Humber College, Section 1

Tie: “Talk to regularly” Average number of ties 18 Range from 0 to 26

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Humber College, Section 2

Subgroups with different level of connections (K-cores)2 ties - green5 ties - blue6 ties - grey7 ties - black8 ties - pink9 ties - red

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End of Lecture: Group Exercises

1. Compare the class at Humber College class with the class at York University. Describe the information flows in them. Discuss the consequences.

2. Who are the best connected students in the Humber College class? Explain why. Use SNA terms if possible. What are the consequences of this connectivity for the students?

3. Imagine Julia is a PR professional in a corporation and Katelyn is the CEO. If Julia wants to tell Katelyn something quickly and CANNOT contact her directly, what should she do? Discuss alternatives.

4. In your friendships network, consider whether the characteristics of your friends and whether or not your friends know each other. Use SNA terms if possible. What are the consequences of these characteristics for you?