A0311
Title: Optimal two-level designs under model uncertainty
Authors: Steven Gilmour - KCL (United Kingdom) [presenting]
Pi-Wen Tsai - National Taiwan Normal University (Taiwan)
Abstract: Two-level designs are widely used for screening experiments where the goal is to identify a few active factors which have major effects. We apply the model-robust $Q_B$ criterion for the selection of optimal two-level designs without the requirement of level balance and pairwise orthogonality. We provide a coordinate exchange algorithm for the construction of $Q_B$-optimal designs for the first-order maximal model and second-order maximal model and demonstrate that different designs will be recommended under different experimenters' prior beliefs. Additionally, we extend the definition of the $Q_B$ criterion to regular and irregular block designs and study the relationship between this new criterion and the aberration-type criteria for blocks. Some trade-offs between orthogonality and confounding will lead to different choice of block designs. Some new classes of model-robust designs which respect experimenters' prior beliefs are found.
