Other SAS/STAT procedures can be used to fit the response surface, but the RSREG procedure is more specialized. PROC RSREG uses a much more compact model syntax than other procedures; for example, the following statements model a three-factor response surface in the REG, GLM, and RSREG procedures:

proc reg; model y=x1 x1*x1 x2 x1*x2 x2*x2 x3 x1*x3 x2*x3 x3*x3; run; proc glm; model y=x1|x2|x3@2; run; proc rsreg; model y=x1 x2 x3; run;

Additionally, PROC RSREG includes specialized methodology for analyzing the fitted response surface, such as canonical analysis and optimum response ridges.

Note that the ADX Interface in SAS/QC software provides an *interactive* environment for constructing and analyzing many different kinds of experiments, including response surface experiments. The
ADX Interface is the preferred interactive SAS System tool for analyzing experiments, since it includes facilities for checking
underlying assumptions and graphically optimizing the response surface; see
*Getting Started with the SAS ADX Interface for Design of Experiments* for more information. The RSREG procedure is appropriate for analyzing experiments in a batch environment.