An aberration criterion for conditional models.

Conditional models with one pair of conditional and conditioned factors in Mukerjee et al. (2017) are extended to two pairs in this paper. The extension includes the parametrization, effect hierarchy, sufficient conditions for universal optimality, aberration, complementary set theory and the strategy for finding minimum aberration designs. A catalog of 16-run minimum aberration designs under conditional models is provided. For five to twelve factors, all 16-run minimum aberration designs under conditional models are also minimum aberration under traditional models.