My main area of research concerns the design of experiments for large numbers of factors and, in particular, screening to find those factors that most influence a response. A long term collaboration with Sue Lewis of Southampton University in England is continuing in this area. We have recently edited a volume of invited papers dealing with many and varied aspects of screening. Together with PhD student Danel Dragulic, we are investigating which of several different designs and analysis methods performs the best for different types of screening tasks. Ph.D. student Hyejung Moon (who is being jointly supervised by Thomas Santner and me) is investigating the use of group screening in computer experiments. I am also involved in developing the theory of construction of three different types of factorial experiments arranged in split-plot and split-lot designs, one project with recently graduated Ph.D. student Tena Katsaounis, one with Derek Bingham and Pritam Ranjan, and the third with Sue Lewis and Rob Stapleton.

In the human decision area, I am working with recently graduated Ph.D. student Qing Liu and with Greg Allenby, Professor of Marketing, in studying the effect on product ratings of various numbers of options provided to subjects in a conjoint experiment. A second project, jointly with Steven MacEachern and recently graduated Ph.D. student Shiling Ruan involves the use of the Poisson race model for modelling human decisions. These research topics form part a large NSF-funded project on hierarchical Bayesian methods in consumer behavior.