Measures of nonlinearity for a biadditive ANOVA model

The biadditive models are ANOVA models extended by quadratic (bilinear) terms which are frequently used in Agronomy and Plant Breeding interpretation of experiments. In a biadditive model, we derived explicit expressions for the intrinsic and parameter-effect measures of nonlinearity. Biadditive models are specific in the sense that they are singular (overparametrized), and regularized by nonlinear parameter constraints, so the approach from Pazman (1999) has been applied, however using advantageously the orthogonal structure of the model under a full design. Two competitive parametrizations of the same model are compared for their influence on the measures of nonlinearity. A review of numerical values obtained from already published results is commented.