Power Analysis

Statistical hypothesis tests are used to address research questions of interest in analytical studies (e.g., studies that attempt to establish relationships between variables). Power is the probability of rejecting the null hypothesis of a statistical test when the null hypothesis is false. High power is desirable for a statistical test, as it implies a low false-negative rate. Power analysis involves the calculation of power, or equivalently, the sample size or detectable effect size given specific power, for a study. Power analysis helps evaluate the performance of a study design in repeated experiments. It provides critical information to help select a design prior to the study initiation that ensures the answer to the research question of interest at the end of the study to be not ...