Abstract
There are compelling reasons to include a discussion of tests for differences between group variances in statistics textbooks. It is important to test for heterogeneity of variance when conducting the t test and the analysis of variance (ANOVA) as well as to test hypotheses about differences between variances as the result of experimental treatment. A survey of 18 introductory statistics textbooks revealed that few cover heterogeneity of variance and that none gives it adequate coverage.
