Chapter 14. Power Analysis for Complex ANOVA Designs

PROC MIXED as a Study Planning Tool

Discussing PROC MIXED as a study planning tool may seem a bit odd for two reasons. First, data analysts consider statistical tools like TTEST, GLM, REG, and MIXED for the _analysis_ of continuous response data (i.e., after study planning and collection are finished). Second, study planning is placed near the end of these pages and not at the beginning. Shouldn't a researcher plan how to collect data before it is analyzed? The reasons for placement of this topic here will be evident in the following pages.

First, read the introductory article on power analysis which first discusses the inputs to a power analysis and then compares PROC POWER, PROC GLMPOWER, and PROC MIXED for power computations for a two-sample t-test.