Understanding and Calculating Power after Two-Way ANOVA using SPSS

This video demonstrates how to understand and calculate statistical power after a two-way ANOVA using SPSS. Statistical power is the percentage chance that the null hypothesis will be rejected, when in reality, the null hypothesis is false. Statistical power is partially based on the effect size of the population, and in this example only the effect size from the sample is available. Caution should be used when interpreting “observed power” based on a sample effect size. The concepts of true positive, true negative, false positive, and false negative are reviewed. The relationship between the probability of a type II error (beta error) and power is reviewed. Alpha error (type I error) is discussed.