Part 4: Power and Sample Size
Explores power and sample size for group-randomized trials (GRTs) with a focus on:
- Cornfield's two penalties of extra variation and limited degrees of freedom (df)
- Strategies to reduce extra variation and increase df
- The seven steps involved in any power analysis
- Estimating the intraclass correlation coefficient (ICC)
- Adaptations required for unbalanced designs
The course also provides an example of a sample size calculation for a simple GRT.
Interested in more information about power and sample size for GRTs?
Visit NIH's Research Methods Resources website for