This is a brief explanation on the menu for analysis of designs for quantitative factors.
The menu item Response surface model ... creates a response surface
analysis with first order (FO) terms, and potentially also two-factor interactions
(TWI) and/or pure quadratic (PQ) terms. The resulting object has class
and can be postprocessed with the subsequent menu items.
The menu item Steepest slope ... supports moving the experimental range towards a more promising area, based on a first order model or on a second order model with a saddle point.
The menu item Plot response surface ... supports creation of contour, perspective or image plots of a response surface model, and can also be used for linear models with quantitative variables.
It is of course also possible to use other analysis facilities within the R-commander,
or to use the command-line facilities offered in package
Box G. E. P, Hunter, W. C. and Hunter, J. S. (2005) Statistics for Experimenters, 2nd edition. New York: Wiley.