Robust designs for approximately polynomial regression

We study designs for the regression model E[Y\x]=Sigma(j=0)(p-1)theta(j)x(j)+x(p) psi(x), where psi(x) is unknown but bounded in absolute value by a given function phi(x). This class of response functions models departures from an exact polynomial response. We consider the construction of designs which are robust, with respect to various criteria, as the true response varies over this class. The resulting designs are shown to compare favourably with others in the literature. (C) 1997 Elsevier Science B.V.