Specify the low and high factor levels for Define Custom Split-Plot Design

Stat > DOE > Factorial > Define Custom Factorial Design > Low/High

Low and High Values for Factors

For each factor in the list, verify that the type and settings are correct. HTC denotes a hard-to-change factor.

Type: Factor levels can be text or numeric. The initial type matches the data type in the worksheet. If a categorical factor uses numeric levels, use Change Data Type so that the levels are text before you define your design.
Low: If the factor is numeric, the initial value matches the minimum numeric value in the column. The minimum and the low level can be different if the design contains a botched run where the factor level is less than the level that you want to use as the low level. If your design contains a botched run with a lower level, type the level you want to treat as the low level for the factor. If the factor is text, type the level that should be the low level.
High: If the factor is numeric, the initial value matches the maximum numeric value in the column. The maximum and the high level can be different if the design contains a botched run where a factor level is greater than the level that you want to use as the high level. If your design contains a botched run with a higher level, type the level you want to treat as the high level for the factor. If the factor is text, type the level that should be the high level.

Note

If you mistype the high or low level for a text factor in the worksheet, Minitab Statistical Software warns that text factors must have exactly two levels when you click OK to define the design.

Worksheet Data Are

Select how the data are recorded in the worksheet.

Coded: High and low levels of numeric factors are coded as -1 and 1. Text factors are coded with numbers instead of text. For numeric factors, Minitab Statistical Software interprets values other than -1 and 1 as botched runs.
Uncoded: High and low levels of the numeric factors are in the units of the data. Levels for text factors are text.