Statistics: Stratified Sampling

Objectives

• Students will be able to identify situations in which stratification might reduce variation.
• Students will recognize that some stratification designs are useful in reducing variation and some are not.
• Students will recognize that random selection of subject(s) must occur within each stratum.
• Students will recognize that the subjects within each stratum should be as similar as possible and different from the subjects in the other strata based on a variable that has the potential to affect the outcome of the study.

Vocabulary

• random selection
• simple random sample (SRS)
• stratified random sample
• stratum(a)
• survey

About the Lesson

This lesson involves determining which of three different sampling methods - a simple random selection design and two stratified selection designs - would be most beneficial in selecting a survey sample within a given context.
As a result, students will:

• Use a simple random sample (SRS) to select survey participants.
• Use two different stratified random sampling designs to select survey participants.
• Compare means and variability for the three sampling designs to determine the most effective design for this context.