Automated software clustering: An insight using cluster labels

Clustering techniques have shown promising results for the architecture recovery and re-modularization of legacy software systems. Clusters that are obtained as a result of the clustering process may not be easy to interpret until they are assigned appropriate labels. Automatic labeling of clusters reduces the time required to understand them and can also be used to evaluate the effectiveness of the clustering process, if the assigned labels are meaningful and convey the purpose of each cluster effectively. In this paper, we present a labeling scheme based on identifiers of an entity. As the clustering process proceeds, keywords within identifiers are ranked using two ranking schemes: frequency and inverse frequency. We present experimental results to demonstrate the effectiveness of our labeling approach. A comparison between the ranking schemes reveals the inverse frequency scheme to form more meaningful labels, especially for small clusters. A comparison of clustering results of the complete and weighted combined algorithms based on labels of the clusters produced by them during clustering shows that the latter produces a more understandable cluster hierarchy with easily identifiable software sub-systems.