Schematic social networks and corresponding network structure curves. Top and bottom panels show two networks that have identical topology, but different distributions of tie strengths. The network in the top panel has a homogeneous distribution of tie strengths while the network in the bottom panel shows a heterogeneous distribution. Edge widths indicate tie strength. The Girvan-Newman clustering algorithm detects highly interconnected subunits regardless of edge weights, and so, at the SRI threshold of 0 both networks have the same number of clusters (a). By removing ties with the SRI values below successive thresholds and re-running the clustering algorithm, the underlying differences in the networks are easily visualized in the network structure curve on the right (b-d).
de Silva et al. BMC Ecology 2011 11:17 doi:10.1186/1472-6785-11-17