Stat > DOE > Response Surface > Create Response Surface Design > Factors
Complete the following steps to specify details about the factors in the design.
Under Name, enter a descriptive name for each factor. By default, Minitab names the factors alphabetically, skipping the letter I.
For continuous factors, enter the high and low levels for each factor. For example, an engineer wants to test two different temperatures and enters 150 for low and 250 for high. By default, Minitab sets the low level of all factors to −1 and the high level to +1.
If you have categorical factors, select the number of levels for each factor and enter the level values.