To specify response surface model terms
main topic     see also 

1    In the Optimal Design dialog box, click Terms.

2    Do one of the following:

·    from Include the following terms, choose linear, linear + squares,
linear + interactions, or full quadratic

·    move the terms you do not want to include in the model from Selected Terms to Available Terms using the arrow buttons

-    to move one or more factors, highlight the desired terms then click or

-    to move all of the terms, click or

You can also move a term by double-clicking it.