ABSTRACT
In this chapter you will:
Learn how to use contrast codes to analyze the significance of any group comparisons you have planned prior to analysis.
Learn how to use a post hoc test to determine, after the fact, exactly which group means differ significantly from each other, given that an omnibus F test was significant.
Learn how to adjust group means when reporting results, given that an analysis of covariance yielded significant results.
Learn how to test whether the assumption of homogeneity of regression, which is required for an analysis of covariance, is warranted.
Analyzing variance, or determining which factors account for significant proportions of criterion variance, whether performing a one-way analysis of variance as in the last chapter or an analysis of covariance as in chapter 11, is only half of the data analytic task. The task is not complete until the specific results have been described. What should be described, and how it should be described, is the topic of this chapter.