Value | Silhouette score meaning (computed from data) | Adjusted Rand index meaning (computed from data and ground truth) |
---|---|---|
< 0 | Observations are closer to the centroid of another cluster than to the centroid of the cluster to which they were assigned | Below chance performance: random guessing would have provided more accurate labelling |
0 | Observations lie exactly between the centroids of their assigned cluster and the nearest of the other clusters | The number of labels assigned by the algorithm that overlap with the ground truth are at chance level |
0.5–0.7 | Evidence for clustering | |
0.7–1.0 | Strong evidence for clustering | |
1 | Perfect alignment of observations and their assigned cluster centroid | Perfect overlap between assigned clusters and ground truth |