Sensitivity Power Analyses

The critical population effect size is computed as a function of

• α,
• 1-β, and
• N.

Sensitivity analyses provide answers to questions such as "What is the effect size a study was able to detect with a power of 1-β = .80, given its sample size and α as specified by the author? In other words, what is the minimum effect size the test was sufficiently sensitive to?"

In addition, sensitivity analyses may be useful before conducting a study to see whether, given a limited N, the size of the effect that can be detected is at all realistic (or, for instance, whether it is way too large to be expected under realistic circumstances).