ANOVA

Analysis of Variance (ANOVA) is used to test the equality of the means of three or more groups based on sample data. ANOVA is really a test of means even though it sounds like a test of variance. Building on the hypothesis testing techniques discussed on the first two weeks, ANOVA uses an F test (rather than a Z or t test) to compare multiple means. A hypothesis test using an F statistic can determine whether three or more sample means are statistically significantly different from each other, otherwise one may conclude that they are from the same population. The concepts of variance and sums of squared differences used in ANOVA can be used to evaluate the output of linear regression, the topic of Week Four.