This paper presents a general method for nding optimal blocking arrangements of pure-level and mixed-level orthogonal designs of resolution 3. The method requires enumeration of all non-isomorphic `parent designs' that include the treatment factors as well as the future blocking factor. For all...

This article will help practitioners select strength-3 designs that are useful for screening both main effects and two-factor interactions. We calculated word-length patterns, correlations of four-factor interaction contrast vectors with the intercept, and ranks of the two-factor interaction...