The Choice of Subsample Size in Two-Stage Sampling
当两阶段抽样的设计参数（方差比和成本比）只知道大致范围时，提出一种最大化最小效率的方法来选择子样本量，并给出简单实用规则。
Abstract This article presents a simple method for choosing the subsample size m in two-stage sampling when the values of the relevant design parameters, the variance ratio and the cost ratio, are not known exactly but can only be assumed to lie within some specific range. Measuring the efficiency of a choice of m by its precision relative to the optimum choice, which depends on the parameters, it is proposed to choose m so that its minimum efficiency, over the specified range of parameters, is maximized. The value of m under this maximin criterion, and its minimum efficiency, are derived. A simple practical rule is also given. The usefulness of the method is discussed and illustrated with examples.