Homogeneity of variance test. For an independent samples t-test, two sets of results are provided along with a statistic you can use to determine which set is appropriate to report. The null hypothesis for Levene's test is that the variances of the two groups are the same. Some suggest using Levene's median test instead. Prism doesn't do this test (yet), but it isn't hard to do by Excel (combined with Prism). To do Levene's test, first create a new table where each value is defined as the absolute value of the difference between the actual value and median of its group. Then run a one-way ANOVA on this new table. Alternatively, you could run a Kruskal-Wallis H Test. For most situations it has been shown that the Welch test is best. Both the Welch and Brown and Forsythe tests are available in SPSS Statistics (see our One-way ANOVA using SPSS Statistics guide). A lack of independence of cases has been stated as the most serious assumption to fail. Expert-verified. Step 1. It is given that, The data of one film with "The Notebook" and other with the film "Documentary about View the full answer Step 2. Unlock. Step 3. Unlock. Answer. The data are in the file Teach.sav. Carry out a one-‐way ANOVA and use planned comparisons to test the hypotheses that: (1) reward results in better exam results than either punishment or indifference; and (2) indifference will lead to significantly better exam results than punishment. Exam Mark. If the p-value for Levene's Test is MORE THAN .05, the assumption of homogeneity of variance has been met and the parametric statistical test can be interpreted. This assumption is important when using independent samples t-tests and one-way ANOVA. Click on the buttons below to see how Levene's Test is conducted and interpreted in SPSS. The assumption of equal variances (i.e. assumption of homoscedasticity) assumes that different samples have the same variance, even if they came from different populations. The assumption is found in many statistical tests, including Analysis of Variance (ANOVA) and Student’s T-Test. The factorial ANOVA has a several assumptions that need to be fulfilled – (1) interval data of the dependent variable, (2) normality, (3) homoscedasticity, and (4) no multicollinearity . Furthermore similar to all tests that are based on variation (e.g. t-test, regression analysis, and correlation analyses) the quality of results is stronger I hope this video helps you understand how to do the Bartlett test, which is used to test homogeneity of variances among groups. IV: Treatment vs. Not (2 levels) From the menu, click on Analyze -> General Linear Model -> Multivaraite…. In the appearance window, move WRAT_R and WRAT_A (Dependent variables) to the Dependent Variables: box & Treat (Independent variable) to the Fixed Factor (s): Then, hit the Options… on bottom right menu. From a new window, move Treat MVDt8.