A Cohen’s D is a standardized effect size which is defined as the difference between your two groups measured in standard deviations. Because the Cohen’s D unit is standard deviations, it can be used when you have no pilot data. As a general guide a Cohen’s D of 0.3, 0.5 and 0.8 corresponds to mild, […]

The calculator is for Sidak corrected multiple t-tests. It’s useful for when you have pilot data and have estimates for the mean of the control group and the standard deviations. It allows you to estimate the number of animals required to detect a range of percentage changes from the control group. Example paragraph: A power analysis […]