Network Network AnalysisAnalysis

by Barry by Barry WellmanWellman

Three Ways to Look at Three Ways to Look at RealityReality

CategoriesCategories All Possess One or More Properties as an Aggregate of All Possess One or More Properties as an Aggregate of

IndividualsIndividuals Examples:Examples: Men, Developed Countries Men, Developed Countries

GroupsGroups (Almost) All Densely-Knit Within Tight Boundary(Almost) All Densely-Knit Within Tight Boundary Thought of as a Solitary Unit Thought of as a Solitary Unit (Really a Special Network)(Really a Special Network) Family, Workgroup, CommunityFamily, Workgroup, Community

NetworksNetworks Set of Connected Units: People, Organizations, NetworksSet of Connected Units: People, Organizations, Networks Can Belong to Multiple NetworksCan Belong to Multiple Networks Examples: Examples: Friendship, Organizational, Inter-, World-Friendship, Organizational, Inter-, World-

System, InternetSystem, Internet

Nodes, Relationships & Nodes, Relationships & TiesTies

Nodes: A Unit That Possibly is ConnectedNodes: A Unit That Possibly is Connected Individuals, Households, Groups, Individuals, Households, Groups,

Organizations, StatesOrganizations, States

Relationships (A Specific Type of Relationships (A Specific Type of Connection)Connection) Gives Emotional SupportGives Emotional Support Sends Money ToSends Money To AttacksAttacks

Ties Ties (One or More Relationships)(One or More Relationships) Friendship (with possibly many relationships)Friendship (with possibly many relationships)

A Network is More Than A Network is More Than The Sum of Its TiesThe Sum of Its Ties

A Network Consists of One or More A Network Consists of One or More NodesNodes Could be Persons, Organizations, Groups, NationsCould be Persons, Organizations, Groups, Nations

Connected by One or More Connected by One or More TiesTies Could be One or More RelationshipsCould be One or More Relationships

That Form Distinct, Analyzable That Form Distinct, Analyzable PatternsPatterns Can Study Patterns of Can Study Patterns of RelationshipsRelationships OR OR TiesTies

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Overview - JournalsOverview - Journals

Wellman founded, Wellman founded, Connections, Connections, 19771977 Informal journal: “Useful” articles, news, gossip, Informal journal: “Useful” articles, news, gossip,

grants, abstracts, book summariesgrants, abstracts, book summaries Bill Richards, Tom Valente edit nowBill Richards, Tom Valente edit now

Lin Freeman founded, Lin Freeman founded, Social Networks, Social Networks, 19781978 Formal journal: Refereed articlesFormal journal: Refereed articles Ronald Breiger now co-editorRonald Breiger now co-editor

David Krackhardt founded, J of David Krackhardt founded, J of Social Social Structure, Structure, 20002000 Online, RefereedOnline, Refereed Lots of visualsLots of visuals Articles Appear Occasionally when their time has Articles Appear Occasionally when their time has

comecome

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Overview – Key BooksOverview – Key Books1)1) Elizabeth Bott, Elizabeth Bott, Family & Social Network, Family & Social Network, 19571957

2)2) J. Clyde Mitchell, J. Clyde Mitchell, Networks, Norms & Institutions, Networks, Norms & Institutions, 19731973

3)3) Holland & Leinhardt, Holland & Leinhardt, Perspectives on Social Network Perspectives on Social Network Research,Research,19791979

4)4) S. D. Berkowitz, S. D. Berkowitz, An Introduction to Structural Analysis, An Introduction to Structural Analysis, 19821982

5)5) Knoke & Kuklinski, Knoke & Kuklinski, Network Analysis, Network Analysis, 19831983

6)6) Charles Tilly, Charles Tilly, Big Structures, Large Processes, Huge Big Structures, Large Processes, Huge Comparisons,Comparisons, 1984 1984

7)7) David Knoke, David Knoke, Political Networks, Political Networks, 19901990

8)8) John Scott, John Scott, Social Network Analysis, Social Network Analysis, 19911991

9)9) Ron Burt, Ron Burt, Structural Holes, Structural Holes, 19921992

10)10) Manuel Castells, Manuel Castells, The Rise of Network Society, The Rise of Network Society, 1996, 20001996, 2000

11)11) Wasserman & Faust, Wasserman & Faust, Social Network Analysis, 1992Social Network Analysis, 1992

12)12) Nan Lin, Nan Lin, Social Capital Social Capital (monograph & reader), 2001(monograph & reader), 2001

13)13) Monge & Contractor, Theories of Communication Networks, Monge & Contractor, Theories of Communication Networks, 20032003

Overview – SoftwareOverview – Software1)1) UCINet – Whole Network AnalysisUCINet – Whole Network Analysis

2)2) MultiNet – Whole Network Analysis MultiNet – Whole Network Analysis

3)3) P*Star – Dyadic AnalysisP*Star – Dyadic Analysis

4)4) Krackplot – Network Visualization Krackplot – Network Visualization

5)5) Pajek – Network Visualization Pajek – Network Visualization

6)6) Personal Network AnalysisPersonal Network Analysis1)1) SPSS/SAS – See Wellman, et al. “How To…” SPSS/SAS – See Wellman, et al. “How To…”

paperspapers

The Social Network The Social Network ApproachApproach

The world is composed of networks The world is composed of networks - not densely-knit, tightly-bounded - not densely-knit, tightly-bounded

groupsgroups

Networks provide flexible means of social Networks provide flexible means of social organization and of thinking about social organization and of thinking about social organizationorganization

Networks have emergent properties of Networks have emergent properties of structure and composition structure and composition

Networks are a major source of social capital Networks are a major source of social capital mobilizable in themselves and from their mobilizable in themselves and from their contentscontents

Networks are self-shaping and reflexiveNetworks are self-shaping and reflexive

Networks scale up to networks of networksNetworks scale up to networks of networks 9

Networked IndividualismNetworked Individualism

Moving from a society bound up in little boxes Moving from a society bound up in little boxes to a multiple network – and networkto a multiple network – and networkinging – – societysociety

Networks are a flexible means of social Networks are a flexible means of social organizationorganization

Networks are a major source of social capital: Networks are a major source of social capital: mobilizable in themselves & from their contentsmobilizable in themselves & from their contents

Networks link:Networks link: PersonsPersons Within organizationsWithin organizations Between organizations and institutionsBetween organizations and institutions

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Barry Wellman co-editor Social Structure: A Network ApproachJAI-Elsevier Press 1998

Little Boxes

Glocalization

Networked Individualism

Ways of Looking at Ways of Looking at NetworksNetworks

Whole Networks & Personal NetworksWhole Networks & Personal Networks Focus on the System or on the Set of IndividualsFocus on the System or on the Set of Individuals

Graphs & MatricesGraphs & Matrices We dream in graphsWe dream in graphs We analyze in matricesWe analyze in matrices

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Whole Social NetworksWhole Social Networks

Comprehensive Set of Role Relationships in a Full Comprehensive Set of Role Relationships in a Full SystemSystem

Analyze Each Role Relationship – Can Combine Analyze Each Role Relationship – Can Combine Composition:Composition: % Women; Heterogeneity; % Weak % Women; Heterogeneity; % Weak

TiesTies Structure: Structure: Pattern of TiesPattern of Ties

Village, Organization, Kinship, Enclaves, World-Village, Organization, Kinship, Enclaves, World-SystemSystem Typical Methods:Typical Methods: Cliques, Blocks, Centrality, Flows Cliques, Blocks, Centrality, Flows (1)(1) What is the Real Structure of an Organization?What is the Real Structure of an Organization? (2) How Does Information Flow Through a Village?(2) How Does Information Flow Through a Village?

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Duality of Persons & Duality of Persons & GroupsGroups

People Link GroupsPeople Link GroupsGroups Link PeopleGroups Link PeopleAn Interpersonal An Interpersonal

Net is an Net is an Interorganizational Interorganizational NetNet

Ronald Breiger 1973Ronald Breiger 1973

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The Dualities of Persons and Groups -- Graphs

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Dualities of Persons and Groups -- Matrices

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Dualities of Persons and Groups: Event-Event Matrix

Neat Whole Network Neat Whole Network MethodsMethods

QAPQAP Regression of MatricesRegression of Matrices

Example: Co-Citation (Intellectual Tie) Example: Co-Citation (Intellectual Tie) Predicts Better than Friendship (Social Tie)Predicts Better than Friendship (Social Tie)To Inter-CitationTo Inter-Citation

Clustering: Clustering: High Density; Tight Boundaries High Density; Tight Boundaries (“Groups”)(“Groups”)

Block ModelingBlock Modeling Similar Role Relationships, Similar Role Relationships, Not Not Necessarily ClustersNecessarily Clusters Canada & Mexico in Same Block – US DominatedCanada & Mexico in Same Block – US Dominated

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Erickson, 1988: From a Matrix > . . .

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. . . To a Block Model

Costs of Whole Network Costs of Whole Network AnalysisAnalysis

Requires a Roster of Entire PopulationRequires a Roster of Entire Population

Requires (Imposition of) a Social BoundaryRequires (Imposition of) a Social Boundary This May Assume What You Want to FindThis May Assume What You Want to Find

Hard to Handle Missing DataHard to Handle Missing Data

Needs Special Analytic PackagesNeeds Special Analytic Packages Becoming Easier to UseBecoming Easier to Use

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Personal Social NetworksPersonal Social Networks

Ptolemaic Ego-Centered ViewPtolemaic Ego-Centered View

Good for Unbounded NetworksGood for Unbounded Networks

Often Uses Survey ResearchOften Uses Survey Research

Example: Example:

(1)(1) Do Densely-Knit Networks Provide More Support? Do Densely-Knit Networks Provide More Support? (structure)(structure)

(2) Do More Central People Get More Support?(2) Do More Central People Get More Support?(network)(network)

(2) Do Women Provide More Support? (2) Do Women Provide More Support? (composition)(composition)

(3) Do Face-to-Face Ties Provide More Support Than (3) Do Face-to-Face Ties Provide More Support Than Internet Ties? Internet Ties? (relational)(relational)

(4) Are People More Isolated Now? (4) Are People More Isolated Now? (ego)(ego)

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