Exercises The 5 exercises below are used to reinforce the concepts students learn in the short course, Power and Sample Size for Longitudinal and Multilevel Study Designs. Exercise 1: Power for a Single Level Cluster Design Exercise 2: Sample Size Analysis for a Longitudinal Study Exercise 3: Power for a Multilevel Study Exercise 4: Sample Size Analysis for a Multilevel Study with Longitudinal Repeated Measures Exercise 5: Sample Size for a Planned Subgroup Analysis