How do you check for equal variance in SPSS?

How do you check for equal variance in SPSS?

The steps for assessing the assumption of homogeneity of variance for ANOVA in SPSS

1. Click Analyze.
2. Drag the cursor over the Compare Means drop-down menu.
3. Click on One-way ANOVA.
4. Click on the continuous outcome variable to highlight it.
5. Click on the arrow to move the outcome variable into the Dependent List: box.

How do you assess assumption of equal variance?

There are two ways to test if this assumption is met:

1. Use the rule of thumb ratio. As a rule of thumb, if the ratio of the larger variance to the smaller variance is less than 4, then we can assume the variances are approximately equal and use the two sample t-test.
2. Perform an F-test.

What is Levene’s test for equality of variances in SPSS?

Levene’s Test of Equality of Variances is used in SPSS to assess meeting the statistical assumption of homogeneity of variance in between-subjects designs. Levene’s Test of Equality of Variances is a simple statistical test to interpret. If the p-value associated with Levene’s test is LESS THAN .

How to test for equality of two variances?

Test if variances from two populations are equal. An F-test (Snedecor and Cochran, 1983) is used to test if the variances of two populations are equal. This test can be a two-tailed test or a one-tailed test.

When to use equality of variances in Proc?

The equality of variances test does not indicate a significant difference in the two variances . Note that this test assumes that the observations in both data sets are normally distributed; this assumption can be checked in PROC UNIVARIATE by using the NORMAL option with the raw data.

Is the F test for equality of two variances sensitive?

Unlike most other tests in this book, the F test for equality of two variances is very sensitive to deviations from normality. If the two distributions are not normal, the test can give higher p -values than it should, or lower ones, in ways that are unpredictable.

When to use group test statistic for equality of means?

A group test statistic for the equality of means is reported for both equal and unequal variances. Both tests indicate a lack of evidence for a significant difference between grazing methods ( and for the pooled test, and for the Satterthwaite test).