Specify the model terms for Analyze Variability

Specify the terms to use in your model. Minitab includes a set of terms based on the order of the model that you specify, or you can choose the terms directly from the list of all available terms.

Include terms in the model up through order

Select the order of the model. When you choose the model order, the terms listed in Selected Terms changes. For example, if you choose 2, the terms change as follows:

• Selected Terms: All main effects and a set of 2-way interactions.
• Available Terms: All higher-order interactions.

Available Terms

Lists all of the terms that you can add to the model.

Selected Terms

Lists all of the terms that will be included in the model.

Use the arrow buttons to move Available Terms to Selected Terms. Select one or more terms in one of the lists, then click an arrow key. The double arrows move all the terms in one list to the other. You can also move a term by double-clicking it.

Include blocks in the model

Select to include blocks in the model. Minitab enables the checkbox if multiple values are in the block column for the design.

Blocks account for the difference that might occur between runs that are performed under different conditions. For more information, go to What is a block?

Include center points in the model

Select to include center points in the model. Minitab enables the checkbox if multiple values are in the center point column for the design.

Center points are runs where numeric factors are set midway between their low and high levels. For more information, go to How Minitab adds center points to a two-level factorial design.