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

• Identify when to use an independent samples ANOVA
• Explain the logic of the ANOVA F ratio
• Explain how measurement error, individual differences, and treatment effects influence then numerator and the denominator of the F ratio
• Write null and research hypotheses using symbols and words
• Complete an ANOVA summary table by computing the degrees of freedom, SSs, MSs, and F ratio
• Define a critical region and determine if you should reject or fail to reject the null hypothesis
• Compute effect sizes and describe them
• Explain when and why post hoc tests are necessary
• Summarize the results of an independent samples ANOVA using American Psychological Association (APA) style
• Use SPSS to compute an independent samples ANOVA, including post hoc tests
• Interpret the SPSS output for an independent samples ANOVA