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Social Network Analysis (in 10 minutes). Nick Crossley. A set of methods for analysing patterns of relationships. Visualising them in graphs. Defining and measuring their properties. Representing and manipulating them in matrices. Often involves:. Multidimensional scaling.
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Social Network Analysis (in 10 minutes) Nick Crossley
A set of methods for analysing patterns of relationships. • Visualising them in graphs. • Defining and measuring their properties. • Representing and manipulating them in matrices.
Often involves: • Multidimensional scaling. • Correspondence analysis. • Matrix algebra. • Cluster analysis. • Conventional stats (regression etc.) • Multilevel modelling • And certainly should involve qualitative methods too
But best known for: • Sociograms (a.k.a. ‘graphs’, ‘network maps’, ‘social network diagrams’). • Graph theory applications/measures.
A graph: relationships between actors involved in the early UK punk movement
DENSITY • The actual number of connections in a network expressed as a proportion of the potential number. • Given as a figure between 0 and 1.
Diameter • The shortest path between the two most distant vertices (vertex = ‘node’) in a network. • Path and distance both measured by ‘degree’ (i.e. links in the chain). • = path/distance of 3
Centrality (of vertices/nodes) • Number of connections (degree centrality). • Cumulative shortest distance to every other vertex in the graph (closeness centrality). • Extent to which lies in the path connecting all other vertices (betweenness centrality).
The focus is on form • Definition of vertices is up to researcher. • Likewise definition of relations. • But of course they must be meaningful and relevant in the context of the project.
Blockmodelling • A method for reducing large data sets. • Theoretically tied to role analysis and a specific conception of social structure (but perhaps problematically so). • Vertices assigned to ‘blocks’ on the basis of ‘structural equivalence’ (or regular equivalence). • Relations between blocks (via their vertices) analysed.
Why bother? • Operationalises (some versions of) the concept of ‘social structure’. • Network positions enable/constrain actors. • Network figurations enable/constrain actors and have effects. • Exploring diffusion. • Exploring structural vulnerability.