ABSTRACT
The goal of experimental design is efciency: collecting the maximum amount of information with the minimum of experimental cost. We do this by making use of symmetry in the experimental design. For example, consider Figure 3.1. The design has three major symmetry planes, denoted by the dotted lines-namely, horizontal (x1), vertical (x2), and diagonal (x1x2)—and admits the following equation:
y = a0 + a1x1 + a2x2 + a12x1x2 + ε, (3.1) where
y is some response of interest a0 through a12 are constants to be determined x1 and x2 are factors of interest ε is the experimental error.
