What is the difference between cluster sampling and stratified sampling?

What is the difference between cluster sampling and stratified sampling?

Cluster sampling involves dividing the population into groups (clusters) and randomly selecting entire clusters, while stratified sampling divides the population into subgroups (strata) and randomly selects from each stratum.

Can you give me an example of each?

Sure! In cluster sampling, if you want to survey students in a school district, you might randomly select a few schools and survey all students in those schools. In stratified sampling, you might divide students by grade level and randomly select students from each grade.

Which method is more accurate?

Stratified sampling is generally more accurate because it ensures representation from all subgroups, while cluster sampling may introduce bias if the selected clusters are not representative.

When should I use one method over the other?

Use stratified sampling when you need to ensure representation from specific subgroups. Use cluster sampling when it's more practical or cost-effective to survey entire groups.