An implementation of N-way repeated measures ANOVA: Effect coding, automated unpacking of interactions, and randomization testing

The paper presents the details of an implementation of repeated measures ANOVA, consisting of a set of functions to organize data and represent contrasts to be tested and run statistical tests. The implementation is focused on uses common in experimental psychology. An arbitrary number of within-subject factors, each with an arbitrary number of levels, can be used. A non-parametric, randomization- and permutation-based formulation of repeated measures ANOVA was defined and implemented. Methods for testing interactions with categorical and continuous between-subject variables are implemented. Post-hoc tests for exploring interactions are automated. Simulations indicate correct control of false positive rate for all types of test. The software provides output with statistics including p-values and partial eta squared. -. An open source implementation of repeated measures ANOVA based on effect coding. -. Generates p-values and automatized unpacking of interactions for N-factor designs. -. A non-parametric test is defined based on permutation tests.