Generate a research question that could be answered by performing an ANCOVA test on the given data. Create a set of hypotheses (alternative and null) for your test. Using th

USING SPSS: ONE-WAY ANALYSIS OF COVARIANCE (ANCOVA)

1. TESTING THE HOMOGENEITY-OF-REGRESSION (SLOPES) ASSUMPTION Before we get started – we must first conduct a test of the homogeneity-of- regression (slopes) assumption. To conduct this test, follow these steps:

1. Click Analyze, click General Linear Model, and then click Univariate

2. Click the dependent variable, then click � to move it to the Dependent Variable box

3. Click the independent variable, then click � to move it to the Fixed Factor(s) box

4. Click the covariate, then click � to move it to the Covariate(s) box

5 Click Model

6 Click Custom under Specify Model

7. Click the independent variable under Factors & Covariates and click � to make it appear in the Model box

8. Click the covariate under Factors & Covariates and click � to make it appear in the Model box

9. Holding down the Ctrl key, click the independent variable (IV) and the covariate (Cov) in the Factors & Covariates box. Check to see that the default option Interaction is specified in the drop-down menu in the Build Term(s) box. If it is not, select it

10. Click � and the IV*Cov should now appear in the Model box

11. Click Continue. This will bring you back to the Univariate screen

12. Click OK

SPSS STEPS FOR ANCOVA PAGE 2

2. CONDUCTING THE ONE-WAY ANCOVA

1. Click Analyze, click General Linear Model, and then click Univariate

2. Click Reset

If you have not exited SPSS – the prior commands will still be shown. As a precaution for avoiding possible errors – click the reset key and begin the procedure from the initial starting point

3. Click the dependent variable, then click � to move it to the Dependent Variable box

4. Click the independent variable, then click � to move it to the Fixed Factor(s) box

5. Click the covariate, then click � to move it to the Covariate(s) box

6. Click on Options

7. In the Factor(s) and Factor Interactions box, click the independent variable

This will provide the adjusted (Estimated Marginal) means that will be used later (if needed) in post hoc procedures

8. Click � to move it to the Display Means for box

9. Select Descriptive statistics in the Display box

10. Select Homogeneity tests in the Display box

11. Click Continue

12. This will bring you back to the Univariate screen…

13. Click Plots

14. Click the independent variable, then click � to move it to the Horizontal Axis: box

15. Click Add

16. Click Continue

17. This will bring you back to the Univariate screen – click OK

3. CONDUCTING (POST HOC) PAIRWISE COMPARISONS

Open the ANCOVA Pairwise Comparisons Syntax from the course website

Once the syntax file is open…

1. Highlight the entire syntax

2. Click Run

3. Click Selection