Modify factors

Stat > DOE > Modify Design > Modify factors > Specify

This topic applies to screening designs, factorial designs, and response surface designs.

Modify the factor names and the factor level values. Usually, you modify factors because you did not specify levels for the factors during design creation. The default levels are set so that the low level is −1 and the high level is 1. For a correct analysis when you analyze the experiment, you must use Modify Design instead of typing the levels directly in the worksheet. For individual runs that have settings that differ from the planned settings, type changes in the worksheet.

For example, an engineer creates a design to study the effects of temperature and pressure. During the design creation in Minitab, the engineer did not specify the factor levels. Thus, Minitab sets the factor levels so that the low level is −1 and the high level is 1. Before collecting the data, the engineer wants to specify the factor levels with more meaningful values.

Note

If you specified factor levels when you created the design, you can use Display Design to change between coded and uncoded factor levels.

Factor: Lists the factors in the design. This column does not take input.
Name: Enter text to change the name of the factors.
Type: Shows whether the factor is text or numeric. This column does not take input.
Low: Enter a value that describes the low value of the factor. For instance, enter 50 for a numeric low value, or enter Low for a text low value.
High: Enter a value that describes the high value of the factor. For instance, enter 100 for a numeric high value, or enter High for a text high value.