Hierarchical Clustering & Cluster Interpretability

School Connect: Intro to DS & AI

Vivek Sivaramakrishnan

Indian Institute of Technology, Madras

Jigsaw

How would you solve a Jigsaw Puzzle?

Typical Process

• Begin by trying to identify 2 pieces that are similar to each other and combine them (cluster).
• Continue this process of combining pieces/clusters till completion.
• This is informally the process of Hierarchical Clustering!

Example

✨Dendrograms✨

Clusters from Dendrograms ✂️

Some terms

• The clustering we just demonstrated is Agglomerative (Bottom-Up) using Single Linkage.

Single Linkage

Complete Linkage

• The linkages require a Distance Matrix.