1. Introduction -- 2. One-way analysis of variance, all categories -- Two groups -- More than two groups -- 3. Two-way analysis of variance, all categories -- Unrelated explanatory variables -- Related explanatory variables -- Special topics -- 4. Analysis of variance, sample of categories -- One-way analysis -- Two explanatory variables -- 5. Other models -- Three explanatory variables -- Latin square design -- Nested designs -- Analysis of variance and regression -- 6. Conclusion.