Extended Central Composite Designs and Their Statistical Properties0

There are several desirable properties that response surface de-signs may have. Sometimes we need designs which have more than one desirable property at the same time. In this paper, we have pro-posed an extended version of central composite design and named it CCD2. We have obtained conditions for orthogonality, rotatability and slope rotatability for the CCD2. CCD2’s that have both orthogonal-ity and rotatability, both orthogonality and slope rotatability over axial directions, and both rotatability and uniform precision also have been obtained