Term
The equation that is used to fit the data consists of various terms. The terms can be of type linear, interactions, quadratic, or cubic.
For example, let F1 and F2 be two factors and R1 the response. The regression equation for R1 can take the form:
R1 = C0 + C1*F1 + C2*F2 + C3*F1*F2 + C4*F1*F1
Here, the Cs are coefficients:
■C1*F1 and C2*F2 are the linear terms
■C3*F1*F2 is an interactions term
■C4*F1*F1 is a quadratic term