It is known that nonnormality, a heteroscedastic error term, or a nonlinearassociation can create serious practical problems when using the conventional analysis of covariance (ANCOVA) method. This article describes a simple ANCOVA method that allows heteroscedasticity, nonnormality, nonlinearity, and multiple covariates. When standard assumptions are met, all indications are that the power of the proposed method compares very favorably with that of the conventional technique.
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