Which sampling method involves randomly selecting entire groups (clusters) and surveying all individuals within those clusters?

Which sampling method involves randomly selecting entire groups (clusters) and surveying all individuals within those clusters?

• A. Simple random sampling
• B. Stratified sampling
• C. Cluster sampling
• D. Systematic sampling

Answer: (C)

Cluster sampling involves randomly selecting whole groups and surveying everyone within those groups. This approach is useful when the population is spread over a wide area or when it’s costly to list every individual. By choosing a few clusters at random and studying all members inside those clusters, you simplify data collection while still aiming to represent the broader population. For example, randomly picking several schools and surveying every student in those schools is a classic cluster sampling scenario. Other methods differ in how the sampling unit is chosen. Simple random sampling selects individuals across the entire population, not entire groups. Stratified sampling divides the population into subgroups and samples from each subgroup, often to ensure representation. Systematic sampling picks every kth person from a list after a random start.

Cluster sampling involves randomly selecting whole groups and surveying everyone within those groups. This approach is useful when the population is spread over a wide area or when it’s costly to list every individual. By choosing a few clusters at random and studying all members inside those clusters, you simplify data collection while still aiming to represent the broader population. For example, randomly picking several schools and surveying every student in those schools is a classic cluster sampling scenario.

Other methods differ in how the sampling unit is chosen. Simple random sampling selects individuals across the entire population, not entire groups. Stratified sampling divides the population into subgroups and samples from each subgroup, often to ensure representation. Systematic sampling picks every kth person from a list after a random start.