Effect Heredity Example
This example illustrates building a model when the Fit Two Level Screening platform identifies a model that does not follow effect heredity.
1. Select Help > Sample Data Library and open Design Experiment/Plackett-Burman.jmp.
2. Select DOE > Classical > Two Level Screening> Fit Two Level Screening.
3. Select Percent Reacted and click Y.
4. Select Feed Rate through Concentration and click X.
5. Click OK.
Figure 10.7 Model Contrasts
TheCatalyst*Stir Rate interaction is highlighted, but the Stir Rate main effect is not. In accordance with the principle of Effect Heredity, you should add the Stir Rate main effect to the model. See Effect Heredity in the Starting Out with DOE section.
6. Click Make Model.
7. Select Stir Rate and click Add in the Construct Model Effects section.
8. Click Run.
Figure 10.8 Partial Fit Model Report
The ^ symbol to the right of the PValue for Stir Rate and Temperature show that while not significant, these effects are contained in significant higher-order effect.