Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
A cluster sample is a sampling method where the population is divided into groups, or clusters, and a random sample of these clusters is selected. All members of the chosen clusters are included in the final sample.
5 Must Know Facts For Your Next Test
Cluster sampling is often used when a population is large and geographically dispersed.
It can reduce travel and administrative costs compared to simple random sampling.
Clusters should ideally be heterogeneous internally but homogeneous between each other to reduce bias.
This method may introduce higher sampling error if the clusters are not representative of the population.
Cluster sampling can be conducted in one-stage (selecting all members from chosen clusters) or two-stage (further sub-sampling within chosen clusters).