Weiming Ke’s research while affiliated with University of Memphis and other places

In a 2 m−p design of resolution IV, some two-factor interactions (2fi's) may be important and should be estimated without confounding with other 2fi's. Four classes of compromise plans that specify certain 2fi's to be important have been discussed in the literature. Compromise plans are said to be clear if they are of resolution IV and all the specified 2fi's are clear. A 2fi is clear if it is not aliased with any main effect or any other 2fi. Clear compromise plans allow joint estimation of all main effects and these clear 2fi's under the weak assumption that all three-factor and higher order interactions are negligible. In this paper, we study the existence and characteristics of clear compromise plans of classes one to four, and give a catalog of clear compromise plans of 32 and 64 runs.

We consider the problem of selecting appropriate 2 m¡p designs when some two-factor interactions are important. Current methods in the literature select designs that permit estimation of the postulated model consisting of the main effects and important two-factor interactions, under the assumption that all of the other effects are negligible. When the effects not in the postulated model are not negligible, they will bias the estimates of the effects in the model. To minimize the contamination of these nonnegligible effects on the model, we propose and study a minimum aberration criterion. We then discuss the application of this new aberration criterion to compromise plans. Finally, we examine how to search for the best designs according to the criterion and present some results for designs of 16 and 32 runs.