An Analysis-of-Means-Type Test for Variances From Normal Populations

Abstract

After a brief review of the literature, a test for homogeneity of variances is presented. The test, which is the variances analog of the analysis of means (ANOM), can be presented in a graphical form. This graphical presentation makes it easy for practitioners to assess both practical and statistical significance. Tables of critical values are presented for balanced designs. A large-sample version of the test, which uses ANOM critical values, is also presented, as well as a version of the test for unbalanced designs for which approximate critical values can be calculated. Monte Carlo results indicate that this test has power comparable to well-known normal-based tests for homogeneity of variances.

KEY WORDS:

• Critical values
• Dirichlet distributions
• Homogeneity of variances
• Simultaneous inference