testing the null hypothesis. If the P-value is less than the signif-icance level, the null hypothesis is rejected, which means that theterm is significant (Lee et al., 2010). Some of the insignificant termsof the model were not eliminated to maintain the model hierarchyand obtain a not significant lack of fit. Eliminating all insignificantterms causes that the adjusted R2(a measure of the amount ofvariation around the mean explained by the model, adjusted forthe number of terms in the model) decreases and the lack of fitbecomes