ABSTRACT
In the last ve chapters, our discussion has dealt with various inferential statistics, including inferences about means. The next six chapters are concerned with different analysis ofvariance (ANOVA) models. Inthis chapter, weconsider the most basic ANOVA model, known asthe one-factor ANOVA model. Recall the independent ttest from Chapter 7 where the means from two independent samples were compared. What ifyou wish to compare more than two means? The answer is to use the analysis of variance. At this point, you may bewondering why the procedure iscalled the analysis ofvariance rather than the analysis ofmeans, because the intent istostudy possible mean differences. One way ofcomparing aset ofmeans istothink interms ofthe variability among those means. Ifthe sample means are all the same, then the variability ofthose means would be0. Ifthe sample means are not all the same, then the variability of those means would be somewhat greaterthan0. Ingeneral,thegreaterthemeandifferencesare,thegreateristhevariabilityofthemeans. Thus,meandifferencesarestudiedbylookingatthevariabilityofthe means; hence, the term analysis ofvariance isappropriate rather than analysis ofmeans (further discussed in this chapter).
