Learning Objectives

Read pages 252-297 in your textbook.

After reading and studying this chapter, you should be able to do the following: 

9.1 Define the independent-samples t test and explain when it is used

9.2 Describe the decision rule for equal variances assumed versus equal variances not assumed

9.3 Explain the purpose of the folded-form F test and Levene’s test in assessing the equality of variances

9.4 Describe the roles of Cohen’s d and Glass’s delta (Δ) in independent t-test calculations