2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

Homogeneity of Variance

The Levene’s F test for equality of variance is the most commonly used statistic, probably because it is provided in SPSS. SPSS steps (version 27) is as follows:

Analyze > Compare Means > One-way ANOVA > Options > Homogeneity of variance test

Table 131: Test for homogeneity of variance

The null hyp othesis of the Levene’s test is that the variances are equal across all samples

2 = σ

2 2 = ….= σ k 2

H 0 : σ 1

The alternative we are testing is that at least the variance are not equal (for at least one pair).

If the p-value is larger than the alpha level (.05 for our example), accept the null hypothesis and assume that the variances are equal. In the illustration p of ..626 is great than .05, so retain the null hypothesis. You have homogeneity of variance! (we do not need the Welch test or the Games-Howell.

147