Stratified sample

Definition

A stratified sample is a type of sampling method where the population is divided into distinct subgroups, or strata, that share similar characteristics. Samples are then randomly selected from each stratum to ensure representation from all subgroups.

5 Must Know Facts For Your Next Test

1. Stratified sampling ensures that each subgroup of the population is adequately represented in the sample.
2. This method reduces sampling bias by accounting for the variability within different strata.
3. Strata are formed based on specific characteristics relevant to the study, such as age, gender, or income level.
4. Random sampling within each stratum helps maintain randomness and reliability in the overall sample.
5. Stratified samples often provide more accurate and reliable results than simple random samples when dealing with heterogeneous populations.

Review Questions

• What is the primary advantage of using a stratified sample over a simple random sample?
• How are strata determined in a stratified sampling method?
• Why might stratified sampling be preferred when studying a diverse population?

Related terms

Simple Random Sample: A sampling method where every member of the population has an equal chance of being selected.

Cluster Sampling: A sampling technique where entire groups, or clusters, are randomly selected instead of individuals.

Systematic Sampling: A method where every nth member of the population is selected after choosing a starting point at random.