ABSTRACT
INTRODUCTION Within subjects (also known as repeated measures) designs focus on approaches involving measurement of the same participants at multiple levels of a factor (also known as the independent variable). Often, these designs involve measurement over two or more time periods. This chapter examines power for one-and two-factor within-subject analysis of variance (ANOVA) designs and trend analyses. Examples focus on calculations and analyses using univariate and multivariate approaches and present SPSS syntax for primary analyses and for sphericity-adjusted tests.
