Definition
A hierarchical clustering approach that builds nested clusters by merging closer clusters.
Detailed Explanation
Agglomerative clustering starts with each point as a cluster and iteratively merges the closest pairs of clusters. It produces a dendrogram showing the hierarchy of clusters. The algorithm requires choosing a linkage criterion (e.g., single, complete, average) and can use various distance metrics.
Use Cases
1. Biological taxonomy 2. Document hierarchies 3. Social network analysis 4. Customer segmentation