Title
The Impact of Random Models on Clustering Similarity.
Abstract
Clustering is a central approach for unsupervised learning. After clustering is applied, the most fundamental analysis is to quantitatively compare clusterings. Such comparisons are crucial for the evaluation of clustering methods as well as other tasks such as consensus clustering. It is often argued that, in order to establish a baseline, clustering similarity should be assessed in the context of a random ensemble of clusterings. The prevailing assumption for the random clustering ensemble is the permutation model in which the number and sizes of clusters are fixed. However, this assumption does not necessarily hold in practice; for example, multiple runs of K-means clustering returns clusterings with a fixed number of clusters, while the cluster size distribution varies greatly. Here, we derive corrected variants of two clustering similarity measures (the Rand index and Mutual Information) in the context of two random clustering ensembles in which the number and sizes of clusters vary. In addition, we study the impact of one-sided comparisons in the scenario with a reference clustering. The consequences of different random models are illustrated using synthetic examples, handwriting recognition, and gene expression data. We demonstrate that the choice of random model can have a drastic impact on the ranking of similar clustering pairs, and the evaluation of a clustering method with respect to a random baseline; thus, the choice of random clustering model should be carefully justified.
Year
DOI
Venue
2017
10.1101/196840
JOURNAL OF MACHINE LEARNING RESEARCH
Keywords
Field
DocType
clustering comparison,clustering evaluation,adjustment for chance,Rand index,normalized mutual information
Data mining,Fuzzy clustering,CURE data clustering algorithm,Artificial intelligence,Cluster analysis,Single-linkage clustering,k-medians clustering,Correlation clustering,Pattern recognition,Determining the number of clusters in a data set,Constrained clustering,Mathematics,Machine learning
Journal
Volume
ISSN
Citations 
18
1532-4435
4
PageRank 
References 
Authors
0.44
12
2
Name
Order
Citations
PageRank
Alexander J. Gates1265.14
Yong-Yeol Ahn22124138.24