Question

Which among the following is not a valid distance specifying criterion between the clusters, in the context of hierarchical clustering?

• A. Single linkage
• B. Group Average
• C. Complete Linkage
• D. Double linkage

Hint:

In hierarchical clustering, the valid distance criteria include single linkage, group average, and complete linkage.

Answer 1

The Correct Option is D

Step 1: Understanding hierarchical clustering.
In hierarchical clustering, the distance between clusters is computed using various criteria like single linkage, group average, and complete linkage. Double linkage is not a valid criterion in this context.

Step 2: Analysis of options.
- (A) Single linkage: Correct, single linkage is a valid criterion where the distance between clusters is defined as the minimum distance between elements in different clusters.
- (B) Group Average: Correct, this is a valid criterion that calculates the average distance between all points in different clusters.
- (C) Complete Linkage: Correct, this defines the distance between clusters as the maximum distance between elements in different clusters.
- (D) Double linkage: Incorrect, double linkage is not a valid criterion used in hierarchical clustering.

Step 3: Conclusion.
The correct answer is (D) Double linkage.