Extended Central Composite Designs for Second-order Model: A Performance Comparison
Ngozi C. Umelo-Ibemere *
Department of Statistics, Federal University of Technology, Owerri, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The prediction capabilities of three types of rotatable extended central composite designs for fitting the second-order response surface model are studied and their performance compared with the widely used central composite design. The methods of comparison employed are graphical using quantile plots, D- and G-efficiencies. All the compared designs have stable prediction variance. None of them is consistently better than the other. However, the second-type extended central composite design and the central composite design with two center points have the highest D- and G-efficiency values respectively.
Keywords: Evolutionary Cytogenetics, D-efficiency, Homosporous ferns, G-efficiency, Multiple origins of polyploidy ferns, prediction variance, quantile plots, rotatability