Learning Objectives

After reading this chapter, you should be able to:

1. Describe two types of research designs used when selecting related samples.

2. Explain why difference scores are computed for the related-samples t test.

3. State three advantages for selecting related samples.

4. Calculate the degrees of freedom for a related-samples t test and locate critical values in the t table.

5. Identify the assumptions for the relatedsamples t test.

6. Compute a related-samples t test and interpret the results.

7. Compute and interpret effect size and proportion of variance for a related-samples t test.

8. Compute and interpret confidence intervals for a related-samples t test.

9. Summarize the results of a related-samples t test in APA format.

10. Compute a related-samples t test and identify confidence intervals using SPSS.