<Para ID="Par1">The definitive screening (DS) design was proposed recently. This new class of three-level designs provides efficient estimates of main effects that are unaliased with any second-order effects. For practical use, we further study the optimal scheme for blocking DS designs. We propose a...</para>

The addition of another fraction to an initial experiment is often necessary to resolve ambiguities involving aliasing of factorial effects. One of the most widely used techniques for the selection of a follow-up experiment is foldover. However, semifoldover (i.e., adding half of a foldover...