The one-way and two-way repeated-measures ANOVA/ANCOVA dialogs compute analysis of variance and analysis of covariance tables for one or two repeated-measures factors and a between-subjects linear model that can include both factors and covariates.
John Fox jfox@mcmaster.ca
The data are assumed to be in "wide" format, with repeated measures corresponding to distinct variables in the active data set. If the data are in "long" format, they can be reshaped to wide format via the Data > Active data set > Reshape data set from long to wide format dialog.
The model is specified in the Design tab in two parts:
The within-subjects design is defined by using the drop-down lists to select the variables that correspond to the levels of the within-subjects factor (in the case of one repeated-measures factor) or the combinations of levels of the within-subjects factors (in the case of two repeated-measures factors, organized as a two-way table). The user can also name the levels of the within-subjects factor(s) and the factor or factors themselves.
The between-subjects model is specified exactly as for a linear model (see linearModel). The model is then fit as a multivariate linear model with the repeated measures as response variables.
In the Options tab, the user can select either multivariate tests (using one of four test statistics) or univariate tests. The tests are performed by the Anova function in the car package.
The means of the repeated measures can optionally be plotted as a function of within- and between-subjects factors, and the means and standard deviations can be printed, using the repeatedMeasuresPlot function in the RcmdrMisc package.
John Fox, Michael Friendly, and Sanford Weisberg, "Hypothesis Tests for Multivariate Linear Models Using the car Package", The R Journal, 5 (1) 39--52, 2013.
linearModel, Anova, repeatedMeasuresPlot