The data in the Donev Mixture sample data table, found in the Design Experiment folder, are based on an example from Atkinson and Donev (1992). The design includes three mixture factors and one non-mixture factor. The response and factors are as follows:
The response is the electromagnetic Damping of an acrylonitrile powder.
The three mixture ingredients are copper sulphate (CuSO4), sodium thiosulphate (Na2S2O3), and Glyoxal.
Though Wavelength is theoretically continuous, the researchers were interested only in predictions at three discrete wavelengths. As a result, Wavelength is treated as a categorical factor with three levels.
Select Help > Sample Data Library and open Design Experiment/Donev Mixture
Click the asterisk next to CuSO4 in the columns panel and select Mixture.
Mixture Column Property Panel for CuSO4
The L PseudoComponent Coding option is selected. See PseudoComponent Coding.
Click Cancel.
Click the asterisk next to Glyoxal in the columns panel and select Mixture.
Click Cancel.
In the Donev Mixture data table, click the green triangle next to the Model script.
Click Run.
Parameter Estimates Report
Select Estimates > Show Prediction Expression from the Response Damping red triangle menu.
Prediction Expression for Damping Model
Suppose that you are interested in predictions at Wavelength L2. Suppose also that Na2S2O3 and Glyoxal are set to their low values, 0.2 and 0 respectively, and that CuSO4 is set to its high value, 0.8. In this case, the predicted Damping equals the parameter estimate for CuSO4 (6.191) plus the parameter estimate for CuSO4*Wavelength[L2] (1.878). You can verify this in the Prediction Profiler.
Select Save Columns > Save Coding Table from the Response Damping red triangle menu.
First Three Columns of Coding Table Showing Coded Mixture Factors

Help created on 9/19/2017