When all experimental runs cannot be performed under homogeneous conditions, blocking can be used to increase the power for testing the treatment effects. Orthogonal blocking provides the same estimator of the polynomial effects as the one that would be obtained by ignoring the blocks. In many...

The purpose of this paper is to discuss the interpretation of dispersion effects in un-replicated fractional factorials from a robust design perspective. We propose an interpretation of dispersion effects as manifested interactions between control factors and unobserved and uncontrolled factors,...