However, sometimes there are no degrees of freedom for error. In this case, assuming effect sparsity, the Screening platform (Analyze > Specialized Modeling > Specialized DOE Models > Fit Two Level Screening) provides a way to analyze the results of a two-level design. The Screening platform accepts multiple responses and multiple factors. It automatically shows significant effects with plots and statistics. For details, see The Fit Two Level Screening Platform topic. For an examples in the current chapter, see Modify Generating Rules in a Fractional Factorial Design and Plackett-Burman Design.