Abstract: The objective of the research is to study and compare
response surface designs: Central composite designs (CCD), Box-
Behnken designs (BBD), Small composite designs (SCD), Hybrid
designs, and Uniform shell designs (USD) over sets of reduced models
when the design is in a spherical region for 3 and 4 design variables.
The two optimality criteria ( D and G ) are considered which larger
values imply a better design. The comparison of design optimality
criteria of the response surface designs across the full second order
model and sets of reduced models for 3 and 4 factors based on the
two criteria are presented.