In a traditional DoE, screening experiments are performed in the early stages of
the process, when it is likely that many of the design variables initially considered
have little or no effect on the response. The purpose is to identify the design
variables that have large effects for further investigation. Genetic Programming has
shown good screening properties (Gilbert et al., 1998), as will be demonstrated in
Section 6.2, which suggests that both the selection of the relevant design variables
and the identification of the model can be carried out at the same time.