A mathematical expression containing one or more terms, each of which consists of a coefficient and a variable(s) raised to some power. Thus *a* + *bx* is a linear polynomial and *a *+ *bx* + *cx*^{2} is a quadratic polynomial in *x. *A polynomial of order *m* includes terms with powers of *x* up to *x*^{m}.* Polynomials will typically provide excellent fits to the calibration data but it is difficult to find a case where polynomials have contributed to forecasting in the social or management sciences. On the contrary, they are associated with poor accuracy. Do not use polynomials unless there is a very strong a priori case. *