Permutation Tests for Effects in Unbalanced Repeated Measures Factorial Designs

We deal with permutation testing for balanced and unbalanced repeated measures designs and we consider a replicated homoscedastic (balanced or unbalanced) factorial design with fixed effects (Milliken, 1984) as the basic experimental plan. It is worth noting that the new permutation approach, presented here, is exact and, being conditional to the sufficient statistic represented by the data matrix it does not require normality of error terms in the linear model for responses. A comparative simulation study has been performed in order to evaluate the power of such exact separate tests.