Post Hoc Power Analysis Calculator Anova

Post hoc power analysis is a crucial aspect of statistical inference, allowing researchers to determine the probability of detecting an effect given the observed data and specified parameters. The ANOVA calculator provided here focuses on post hoc power analysis for analysis of variance (ANOVA), a statistical method used to analyze the variation in a dataset.

1. Enter the number of groups (n), the number of observations per group (k), the significance level (alpha), and the effect size (eta-squared).
2. Click the “Calculate” button.
3. View the results below the calculator, including the power, observed effect size, and a chart illustrating the relationship between effect size and power.

The power of a statistical test is calculated using the following formula:

Power	=	1 – β
where		β = probability of a Type II error (false negative)

The probability of a Type II error is calculated using the non-central t-distribution:

For more information on post hoc power analysis, see the following authoritative sources:

• University of North Carolina at Chapel Hill
• Nature Methods