Specify what to do with a nonhierarchical model and the treatment of hierarchy when you use stepwise selection. The changes you make to the defaults remain until you change them again, even after you exit Minitab.
 What to do when the specified model is nonhierarchical

 Prompt me: Minitab displays a dialog box to ask whether to use a nonhierarchical model or to make the model hierarchical.
 Add terms to make the model hierarchical: Minitab adds the displayed terms to produce a hierarchical model.
 Use the specified nonhierarchical model: Minitab doesn't add the terms.
 Model hierarchy in Stepwise

 Hierarchical model requirement if potential terms are hierarchical

If you require a hierarchical model, choose the types of terms that must be hierarchical.
 Require a hierarchical model at each step: Minitab can add or remove only terms that maintain hierarchy.
 Add terms at the end to make the model hierarchical: Initially, Minitab follows the standard rules of the stepwise procedure. At the final step, Minitab adds the terms that produce a hierarchical model, even if their pvalues are greater than the alphatoenter.
 Do not require a hierarchical model: The final model can be nonhierarchical. Minitab adds and removes terms based only on the rules of the stepwise procedure.
 Terms affected by the hierarchical model requirement

 All terms: Terms that include continuous and/or categorical variables must be hierarchical.
 Terms with categorical predictors: Only terms that include categorical variables must be hierarchical.
 How many terms can enter if requiring hierarchy at each step

If you require hierarchy at each step, choose the number of terms that Minitab can add at each step in order to maintain hierarchy.
 At most one term can enter at each step: A higherorder term can enter the model only if hierarchy is maintained when adding that single term. All lowerorder terms that comprise the higherorder must already be in the model.
 Extra terms can enter to maintain hierarchy: A higherorder term can enter the model even if it produces a nonhierarchical model. However, the terms that are necessary to produce a hierarchical model are also added, even if their pvalues are greater than the alphatoenter.