Clustering

Question 1

Linkage methods

Answer 1

1. Single linkage -> nearest neighbor
2. Complete linkage -> furthest neighbor
3. average linkage -> cluster centroids
4. Ward‘s method -> middle point between relevant items

Question 2

Dendogram & Agglomeration schedule

Answer 2

• > „LENGTH“ of line -> power of cluster
• > aim at minimum amount of clusters with maximal power
• > inflection point in agglo schedule
• > biggest drop in coefficient value

Question 3

Two-stage clustering

Answer 3

1. Hierarchical clustering to define number of clusters and initial centroids
2. Non-hierarchical clustering with centroids as input