Level
Levels are the number of possible values that can be taken by a factor.
Values: In most screening designs the factors have 2 levels. In RSM designs they typically have 3 levels. It is also possible to have some factors at 2 levels and others at 3 or more levels.
Design objective: | Number of levels: |
|---|
Screening | 2 |
Quadric Surface | 3 |
Cubic Surface | 4 |
Discrete | # of levels for each variable entered |