Optimizing composite sampling protocols

Composite samples are often used in environmental studies to reduce costs by decreasing the number of expensive tests that have to be performed. Statistical models for composite sampling are discussed, and procedures are given for determining the optimal number of primary sampling units to include in each composite sample. For the problem of comparison of means, methods are presented (a) to find the optimum sampling protocol that stays within a fixed budget and (b) to find the least costly sampling protocol that is still able to reliably detect a specified difference in means.