Silhouette score (not currently implemented)

Calculation

Gives the ratio between the cohesiveness of a cluster and its separation from other clusters. Values for silhouette score range from -1 to 1.

Expectation and use

A good clustering with well separated and compact clusters will have a silhouette score close to 1. A low silhouette score (close to -1) indicates a poorly isolated cluster (both type I and type II error).

Literature

Introduced by [Rousseeuw].