Quality Threshold Clustering

Abstract

Quality Threshold is a clustering algorithm without specifying the number of clusters. It uses the maximum cluster diameter as the parameter to control the quality of clusters.

Synonyms

Quality threshold

Definition

Quality Threshold (QT) clustering (Heyer et al. 1999) is a partitioning clustering algorithm originally proposed for gene clustering. The focus of the algorithm is to find clusters with guaranteed quality. Instead of specifying K, the number of clusters, QT uses the maximum cluster diameter as the parameter.

The basic idea of QT is as follows: form a candidate cluster by starting with a random point and iteratively add other points, with each iteration adding the point that minimizes the increase in cluster diameter. The process continues until no point can be added without surpassing the diameter threshold. If surpassing the threshold, a second candidate cluster is formed by starting with a point and repeating the procedure. In order to achieve reasonable...