Evaluation and Comparison of Three Classes of Central Composite Designs
Fidelia Chinenye Kiwu-Lawrence
*
Department of Statistics, Abia State University Uturu, Abia State, Nigeria.
Lawrence Chizoba Kiwu
Department of Statistics, Federal University of Technology, Owerri, Nigeria.
Desmond Chekwube Bartholomew
Department of Statistics, Federal University of Technology, Owerri, Nigeria.
Chukwudi Paul Obite
Department of Statistics, Federal University of Technology, Owerri, Nigeria.
Akanno Felix Chikereuba
Department of Statistics, Federal University of Technology, Owerri, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Three classes of Central Composite Design: Central Composite Circumscribed Design (CCCD), Central Composite Inscribed Design (CCID) and Central Composite Face-Centered Design (CCFD) in Response Surface Methodology (RSM) were evaluated and compared using the A-, D-, and G-efficiencies for factors, k, ranging from 3 to 10, with 0-5 centre points, in other to determine the performances of the designs under consideration. The results show that the CCDs (CCCD, CCFD and CCID) are at their best when the G-efficiency is employed for all the factors considered while the CCID especially behaves poorly when using the A- and D-efficiencies.
Keywords: Response surface methodology, central composite circumscribed design, central composite inscribed design, central composite face-centered design, A-; D-; and G-Efficiencies