Initialization methods for optimum average silhouette width clustering
This work addresses the need for a unified clustering approach without prior knowledge of cluster numbers, offering incremental improvements in clustering quality assessment for data analysis applications.
The authors tackled the problem of simultaneously estimating the number of clusters and performing clustering by optimizing average silhouette width, proposing the OSil algorithm that outperformed various existing methods in simulation studies, showing superior clustering quality and better estimation of cluster numbers.
A unified clustering approach that can estimate number of clusters and produce clustering against this number simultaneously is proposed. Average silhouette width (ASW) is a widely used standard cluster quality index. A distance based objective function that optimizes ASW for clustering is defined. The proposed algorithm named as OSil, only, needs data observations as an input without any prior knowledge of the number of clusters. This work is about thorough investigation of the proposed methodology, its usefulness and limitations. A vast spectrum of clustering structures were generated, and several well-known clustering methods including partitioning, hierarchical, density based, and spatial methods were consider as the competitor of the proposed methodology. Simulation reveals that OSil algorithm has shown superior performance in terms of clustering quality than all clustering methods included in the study. OSil can find well separated, compact clusters and have shown better performance for the estimation of number of clusters as compared to several methods. Apart from the proposal of the new methodology and it's investigation the paper offers a systematic analysis on the estimation of cluster indices, some of which never appeared together in comparative simulation setup before. The study offers many insightful findings useful for the selection of the clustering methods and indices for clustering quality assessment.