Exploratory Social Network Analysis Chapter 12: Blockmodels

1. Blockmodels
Exploratory Social Network Analysis, Part V, Chapter XII

2. Modeling View Change

3. What’s the Advantage?

4. Definitions
• Adjacency Matrix
• Incident Matrix  2-Mode Nets
• Isomorphic Network  Renumbering
• Permutation

5. Structural Equivalence
• Complete Block
• Null Block
• Image Matrix
Defining the Clusters Blocks
Core Periphery
Core Complete Complete
Periphery Complete Null with Error
Shrunk Net Image Matrix

6. Dissimilarity
Dendrogram: hierarchical clustering
Dissimilarity Score

7. Example: Metal Exportation

8. Generalized Equivalence
Generalized Blockmodeling
Regular Equivalence
• A regular block contains at least one arc in each row and in each column
• Example:
All the Ministers Advise PM
Advisors Must Advise at Least 1 Minister
User Defined

9. Adjacency Matrix
Double Click
Permutations:
Operations > Partition + Permutation > Reorder Partition & Partition > Make a Permutation
Dissimilarity
Cluster > Create Complete Cluster.
Operations > Network + Cluster > Dissimilarity.
Operations > Network + Cluster > Dissimilarity > Network based > Options > Report Matrix
Blockmodeling
Network > Create Partition > Blockmodeling*
Partitions > Info > Cramer’s V, Rajski.