Indicator function based on complex contrasts and its application in general factorial designs

A factorial design can be uniquely determined by an indicator function which is constructed by means of orthogonal contrasts. Since the orthogonal contrasts are not unique, invariant measures are preferred. However, some particular orthogonal contrasts may express more information about designs than the others and be worth our attention. In this paper, a kind of indicator function based on orthogonal complex contrasts is introduced to represent general factorial designs and its significance on projection designs is presented. Based on this function, a generalized resolution and a new aberration criterion are developed to rank combinatorially non-isomorphic designs with prime levels. Some results and comparison are provided by means of examples.