CONSTRAINED RANDOMIZATION IN A THERAPEUTIC EFFICACY TRIAL

The use of valid constrained randomization is presented for a therapeu tic efficacy trial. The construction and evaluation of randomization s chemes are studied for two treatment replicates per block and for hypo thesized linear gradients. Two different isomorphism classes of design s are compared using the variance of the mean squared error criterion. The results indicate that valid constrained randomization schemes can be constructed that are superior to ordinary randomization. A mastiti s efficacy trial provided the specific problem to be solved.