https://doi.org/10.1351/goldbook.10077
Equation describing the response as a function of values of the factors.
Notes:
- The model can be based on knowledge of the chemistry or physics of the system, but usually the model is empirical, being linear or quadratic with interaction terms.
- To obtain information about the significance of effects, data is usually mean centered and assessed against a coded experimental design.
Example: The yield of a synthesis is modelled in terms of the temperature \(T\) and concentration of a reactant \(c\): \[\hat Y = {\hat \beta}_{0} + {\hat \beta}_{1}T + {\hat \beta}_{2}c + {\hat \beta}_{11}T^{2} + {\hat \beta}_{22}c^{2} + {\hat \beta}_{12}Tc\]