Comparison of Definitive Screening and Standard Screening Designs for Continuous Factors compares some of the properties of definitive screening designs and standard screening designs for designs containing only continuous factors. When quadratic effects are mentioned, the standard screening designs are assumed to have center points. These properties are described more fully in the remainder of this section.
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Identify the cause of nonlinear effects while avoiding confounding any terms up to second order. So not only can you detect nonlinearity, as you might with center points in a traditional screening design, but you can identify the responsible factors.
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All quadratic effects are estimable in models comprised only of main effects and quadratic terms. This enables you to identify the factors that account for nonlinearity. Note that traditional screening designs with added center points do not allow estimation of all quadratic effects in models consisting of main and quadratic effects.
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To view the absolute values of the correlations among effects, use the Color Map on Correlations provided as part of the Design Evaluation outline in the Definitive Screening Design window. You can compare the aliasing structure of definitive screening designs to that of other designs by comparing their color maps on correlations. For details, see Color Map on Correlations in Evaluate Designs.
For details, see Structure of Definitive Screening Designs. For information on definitive screening designs with blocks, see Blocking in Definitive Screening Designs. For suggestions on how to analyze data obtained using definitive screening designs, see Analysis of Experimental Data.