Evidence-Based Practice / Unit 22 EBP 3184 short lesson, about 20 seconds
Stratification
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The idea
Stratification divides a population into subgroups and samples within each, so that a subgroup small in the population is still represented in the study.
In practice
Sampling separately from each age band, so the oldest patients are not lost in a simple random draw.
Where people slip
Stratifying on a variable you have not measured is impossible, so stratification requires deciding in advance what differences matter.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
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