Communities validity: methodical evaluation of community mining algorithms

Reihaneh Rabbany, Mansoureh Takaffoli, Justin Fagnan, Osmar R. Zaïane, Ricardo J. G. B. Campello

Abstract: Grouping data points is one of the fundamental tasks in data mining, which is commonly known as clustering if data points are described by attributes. When dealing with interrelated data, that is represented in the form a graph wherein a link between two nodes indicates a relationship between them, there has been a considerable number of approaches proposed in recent years for mining communities in a given network. However, little work has been done on how to evaluate the community mining algorithms. The common practice is to evaluate the algorithms based on their performance on standard benchmarks for which we know the ground-truth. This technique is similar to external evaluation of attribute-based clustering methods. The other two well-studied clustering evaluation approaches are less explored in the community mining context; internal evaluation to statistically validate the clustering result and relative evaluation to compare alternative clustering results. These two approaches enable us to validate communities discovered in a real-world application, where the true community structure is hidden in the data. In this article, we investigate different clustering quality criteria applied for relative and internal evaluation of clustering data points with attributes and also different clustering agreement measures used for external evaluation and incorporate proper adaptations to make them applicable in the context of interrelated data. We further compare the performance of the proposed adapted criteria in evaluating community mining results in different settings through extensive set of experiments.