Network Analysis by Barry Wellman

1. Network Analysisby Barry Wellman

3. Three Ways to Look at Reality • Categories • All Possess One or More Properties as an Aggregate of Individuals • Examples: Men, Developed Countries • Groups • (Almost) All Densely-Knit Within Tight Boundary • Thought of as a Solitary Unit (Really a Special Network) • Family, Workgroup, Community • Networks • Set of Connected Units: People, Organizations, Networks • Can Belong to Multiple Networks • Examples: Friendship, Organizational, Inter-, World-System, Internet

4. Nodes, Relationships & Ties • Nodes: A Unit That Possibly is Connected • Individuals, Households, Groups, Organizations, States • Relationships (A Specific Type of Connection) • Gives Emotional Support • Sends Money To • Attacks • Ties (One or More Relationships) • Friendship (with possibly many relationships)

5. A Network is More Than The Sum of Its Ties • A Network Consists of One or More Nodes • Could be Persons, Organizations, Groups, Nations • Connected by One or More Ties • Could be One or More Relationships • That Form Distinct, Analyzable Patterns • Can Study Patterns of Relationships OR Ties

6. Overview - Journals • Wellman founded, Connections, 1977 • Informal journal: “Useful” articles, news, gossip, grants, abstracts, book summaries • Bill Richards, Tom Valente edit now • Lin Freeman founded, Social Networks, 1978 • Formal journal: Refereed articles • Ronald Breiger now co-editor • David Krackhardt founded, J of Social Structure, 2000 • Online, Refereed • Lots of visuals • Articles Appear Occasionally when their time has come

7. Overview – Key Books • Elizabeth Bott, Family & Social Network, 1957 • J. Clyde Mitchell, Networks, Norms & Institutions, 1973 • Holland & Leinhardt, Perspectives on Social Network Research,1979 • S. D. Berkowitz, An Introduction to Structural Analysis, 1982 • Knoke & Kuklinski, Network Analysis, 1983 • Charles Tilly, Big Structures, Large Processes, Huge Comparisons, 1984 • David Knoke, Political Networks, 1990 • John Scott, Social Network Analysis, 1991 • Ron Burt, Structural Holes, 1992 • Manuel Castells, The Rise of Network Society, 1996, 2000 • Wasserman & Faust, Social Network Analysis, 1992 • Nan Lin, Social Capital (monograph & reader), 2001 • Monge & Contractor, Theories of Communication Networks, 2003

8. Overview – Software • UCINet – Whole Network Analysis • MultiNet – Whole Network Analysis • P*Star – Dyadic Analysis • Krackplot – Network Visualization • Pajek – Network Visualization • Personal Network Analysis • SPSS/SAS – See Wellman, et al. “How To…” papers

9. The Social Network Approach • The world is composed of networks - not densely-knit, tightly-bounded groups • Networks provide flexible means of social organization and of thinking about social organization • Networks have emergent properties of structure and composition • Networks are a major source of social capital mobilizable in themselves and from their contents • Networks are self-shaping and reflexive • Networks scale up to networks of networks

10. Networked Individualism • Moving from a society bound up in little boxes to a multiple network – and networking – society • Networks are a flexible means of social organization • Networks are a major source of social capital: mobilizable in themselves & from their contents • Networks link: • Persons • Within organizations • Between organizations and institutions

11. Little Boxes Glocalization Networked Individualism Barry Wellman co-editor Social Structure: A Network ApproachJAI-Elsevier Press 1998

12. Ways of Looking at Networks • Whole Networks & Personal Networks • Focus on the System or on the Set of Individuals • Graphs & Matrices • We dream in graphs • We analyze in matrices

13. Whole Social Networks • Comprehensive Set of Role Relationships in a Full System • Analyze Each Role Relationship – Can Combine • Composition: % Women; Heterogeneity; % Weak Ties • Structure: Pattern of Ties • Village, Organization, Kinship, Enclaves, World-System • Typical Methods: Cliques, Blocks, Centrality, Flows • (1)What is the Real Structure of an Organization? • (2) How Does Information Flow Through a Village?

14. Duality of Persons & Groups • People Link Groups • Groups Link People • An Interpersonal Net is an Interorganizational Net • Ronald Breiger 1973

15. The Dualities of Persons and Groups -- Graphs

16. Dualities of Persons and Groups -- Matrices

17. Dualities of Persons and Groups: Event-Event Matrix

18. Neat Whole Network Methods • QAP • Regression of Matrices • Example: Co-Citation (Intellectual Tie) Predicts Better than Friendship (Social Tie) To Inter-Citation • Clustering: High Density; Tight Boundaries (“Groups”) • Block Modeling • Similar Role Relationships, Not Necessarily Clusters • Canada & Mexico in Same Block – US Dominated

19. Erickson, 1988: From a Matrix > . . .

20. . . . To a Block Model

21. Costs of Whole Network Analysis • Requires a Roster of Entire Population • Requires (Imposition of) a Social Boundary • This May Assume What You Want to Find • Hard to Handle Missing Data • Needs Special Analytic Packages • Becoming Easier to Use

22. Personal Social Networks • Ptolemaic Ego-Centered View • Good for Unbounded Networks • Often Uses Survey Research • Example: • (1)Do Densely-Knit Networks Provide More Support? (structure) • (2) Do More Central People Get More Support?(network) • (2) Do Women Provide More Support? (composition) • (3) Do Face-to-Face Ties Provide More Support Than Internet Ties? (relational) • (4) Are People More Isolated Now? (ego)