Repeated Measures ANOVA

This chapter begins with a sidebar note to instructors reminding instructors that the calculations for the Repeated Measures ANOVA are particularly challenging; thus, it may be best to learn the concepts and use statistical software for computations. The One-Way Repeated Measures ANOVA is introduced in terms of its similarity to the Repeated Measures t Test, learned in Chap. 6 , but allows for more than two treatments to be applied to participants. Like Chap. 7 , this chapter utilizes two examples to demonstrate concepts and calculations: in the first example, we attempt to reduce stress over time using meditation, and in the second, we attempt to increase young children’s reading skills over time by implementing a reading tutoring program. Through both examples, students learn how to calculate the supporting statistics, including treatment and participant totals, treatment means, and the Grand Mean. The data are then reorganized to allow for demonstration of calculations of all of the Sums of Squares: Sums of Squares-Total, Sums of Squares-Between, Sums of Squares-Subjects, and Sums of Squares-Error. Degrees of freedom are calculated, all summary statistics are organized into the Source Table, and the F-ratio is calculated. Similarly to Chap. 7 , students are taught about hypothesis testing with the Repeated Measures ANOVA and use the F-distribution to locate the critical value of F. Post-hoc comparisons are calculated and interpreted using Tukey’s Honestly Significant Difference, and effect size is calculated using omega-squared. Results are reported in APA (seventh edition) formatting. The chapter concludes with a brief summary of key concepts. Step-by-step instructions for completing this analysis using Excel are presented, as well as critical thinking questions and practice problems.