Two-level designs of strength 3 and up to 48 runs


Eric D. Schoen, Faculty of Applied Economics, University of Antwerp, Prinsstraat 13, 2000 Antwerp, Belgium. E-mail:


Summary.  The paper will help practitioners to 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 matrices for all non-equivalent two-level orthogonal arrays of strength 3 and run sizes up to 48. On the basis of these characteristics, there are a limited number of designs that can be recommended for practical use.