Q. What is the primary method used to determine the optimal number of clusters in K-means?
A.
Elbow method
B.
Silhouette analysis
C.
Cross-validation
D.
Grid search
Solution
The elbow method is a common technique used to determine the optimal number of clusters in K-means by plotting the explained variance against the number of clusters.
Q. What type of data is hierarchical clustering particularly useful for?
A.
Large datasets with millions of records
B.
Data with a clear number of clusters
C.
Data where relationships between clusters are important
D.
Data that is strictly numerical
Solution
Hierarchical clustering is particularly useful for data where understanding the relationships between clusters is important, as it provides a visual representation of these relationships.
Correct Answer:
C
— Data where relationships between clusters are important