Abstract
Clustering data into sensible groupings as a fundamental and effective tool for efficient data organization, summarization, understanding, and learning has been the subject of active research in several fields, such as statistics (Hartigan, 1975; Jain & Dubes, 1988), machine learning (Dempster, Laird & Rubin, 1977), information theory (Linde, Buzo & Gray, 1980), databases (Guha, Rastogi & Shim, 1998; Zhang, Ramakrishnan & Livny, 1996), and bioinformatics (Cheng & Church, 2000) from various perspectives and with various approaches and focuses. From an application perspective, clustering techniques have been employed in a wide variety of applications, such as customer segregation, hierarchal document organization, image segmentation, microarray data analysis, and psychology experiments.