What does the Coherence score measure within a Cluster?

The Coherence score is a metric that evaluates the conceptual similarity of documents within a cluster. It quantifies how closely related the documents are in terms of shared themes, topics, or ideas. A high Coherence score indicates that the documents are closely aligned in content, suggesting that they form a meaningful group centered around a specific concept or subject matter.

This concept is essential in fields like machine learning and information retrieval, where clustering documents is common. A strong Coherence score can enhance the usefulness of the cluster, making it easier for users to identify relevant information quickly.

In contrast, measures such as the number of documents in a cluster or the visibility of the cluster do not address the quality of the content's similarity. Similarly, the title of the cluster simply serves as a label and does not inherently reflect the underlying relationships among the documents. Thus, the Coherence score focuses specifically on the conceptual relationships, validating why the conceptual similarity of documents is the correct aspect being measured.