2(N-L) DESIGNS WITH WEAK MINIMUM ABERRATION

Since not all 2(n-l) fractional factorial designs with maximum resolut ion are equally good, Fries and Hunter introduced the minimum aberrati on criterion for selecting good 2(n-l) fractional factorial designs wi th the same resolution. We modify the concept of minimum aberration an d define weak minimum aberration and show the usefulness of this new d esign concept. Using some techniques from finite geometry, we construc t 2(n-l) fractional factorial designs of resolution III with weak mini mum aberration. Further, several families of 2(n-l) fractional factori al designs of resolution III and IV with minimum aberration are obtain ed.