Table 1 Validation metrics.

Validation metrics used for testing the quality of a clustering result and the measures on which they are based.

MetricReferencesMeasures
RMSSTD(34)Compactness
RS(35)
Modified Hubert’s Γ statistic(36)
K-nearest neighbor consistency(37)Connectedness
Connectivity(38)
Determinant ratio index(62)
SD validity index(35)Separation
Pseudo-F statistic
(Calinski-Harabasz)
(39)Combination of
compactness
and separation
Dunn index(40)
Silhouette width(41)
Davies-Bouldin index(41)
Gap statistic(43)
Rand index(44)Similarity between solutions