Table 2. Discrimination of the Correct Interaction Model

Discrimination of the correct interaction model was based on the number of trials out of a total of ten in which either the additive or the second or third order polynomial models were selected on the basis of ELS objective function and MDAWR. The underlying surface model was a second order interaction, as was correctly estimated using MDAWR in those studies with 20 and 40 subjects.

ELS = extended least squares objective function; MDAWR = median absolute weighted residual.