SELECTION USING DIFFERENCE AND RATIO OF SUCCESS PROBABILITIES

Abstract

A fixed sample procedure for selecting the better of two negative binomial populations in the framework of indifference zone approach is presented. The difference and ratio of success probabilities are used simultaneously to overcome the dependence of mean and variance of negative binomial populations. The resulting sample sizes required to achieve the specified probability of correct selection are observed to be lower compared to the procedure involving only one distance measure. The normal approximation is derived and compared with the exact procedure with respect to the associated sample sizes.