<aside> 💡

The ‘silhouette score’ is a metric used to evaluate the quality of clustering by measuring how similar each point is to its own cluster compared to other clusters.

</aside>

A high silhouette score suggests that clusters are compact and well-separated from each other.

The score ranges from -1 to 1, where a high value indicates that the point is well-matched to its own cluster and poorly matched to neighbouring clusters.

The calculation of the silhouette score involves two distances: the mean intra-cluster distance (a) and the mean nearest-cluster distance (b) for each sample. The silhouette score SSS for each point is computed as:

$$ S = \frac{b - a}{\max(a, b)} $$

image.png


Next reading:

Davies-Bouldin Index