Definition
A type of Central Composite Design (CCD) used when there is evidence of curvature in the relationship of the response variable with the predictors or when a more complex model is needed to characterize the response surface adequately. It is formed by adding at least one center point and four axial/star points at a specified distance from the center of the design. Thus, this design requires five levels for each factor under study.
See Also
Central Composite Design