SAS Macros for Analysis of Unreplicated 2^k and 2^k-p Designs with a Possible Outlier

Abstract

Many techniques have been proposed for judging the significance of effects in unreplicated 2^k and 2^k-p designs. However, relatively few methods have been proposed for analyzing unreplicated designs with possible outliers. Outliers can be a major impediment to valid interpretation of data from unreplicated designs. This paper presents SAS macros which automate a manual method for detecting an outlier and performing an analysis of data from an unreplicated 2^k or 2^k-p design when an outlier is present. This method was originally suggested by Cuthbert Daniel and is based on the normal or half normal plot of effects. This automated version was shown in simulation studies to perform better than other procedures proposed to do the same thing.