Statistical power is a fundamental consideration when designing research experiments. It goes hand-in-hand with sample size. The formulas that our calculators use come from clinical trials, epidemiology, pharmacology, earth sciences, psychology, survey sampling ... basically every scientific discipline.
Sample estimation size should be based on the pri-mary outcome measure, but if there is more than one outcome then the largest sample size should be chosen so that all the outcome measures are fully powered. Response Rate After the sample size has been calculated, it will need to be increased depending on the expected response rate.