Analysis of variance

Summary

Analysis of variance, or ANOVA, is a family of methods that split the total variation of a response into parts. Each part is due to one source, such as treatment groups or random error. Its best known use is to test whether several group means are equal. The test compares the variation between groups with the variation within groups through an F-test. It was developed by Ronald Fisher for agricultural experiments and is a central tool of design of experiments. The fixed-effects models of ANOVA are special cases of the general linear model.