Outline
1. Exponential random graph models
2. Model specification and homogeneous Markov random graphs
A critical analysis

3.   Model specification: two suggestions*
Alternating k-star hypothesis
Independent 2-paths and k-triangles
4.   Example: modelling mutual collaboration in a law firm*
5.   Model specification: what have we learnt?
*based on Snijders, Pattison & Robins (in preparation)