The success of triangle completion depends on the module mixing.

<p>Similarity between the community structure of the original network and the perturbed networks for three different average degrees as a function of the module mixing parameter . In panel A the similarity is quantified in terms of the normalized mutual information (NMI) and in panel B the similarity is quantified in terms of the module size ratio. Filled lines and circles correspond to triangle completion and dashed lines and open circles correspond to random link addition. No links were removed prior link addition and the number of links were doubled in all networks by link addition. Each point corresponds to an average over 100 networks.