Singer J
Chinoin Pharmaceutical and Chemical Works Ltd., Clinical Research Unit, Budapest, Hungary.
Stat Med. 1997 Dec 30;16(24):2805-11. doi: 10.1002/(sici)1097-0258(19971230)16:24<2805::aid-sim676>3.0.co;2-b.
This paper contains a short generalization of a known method for sample size determination in the case of more than two parallel groups. The term 'set of allocation ratios' corresponding to the allocation ratio from the two-group design is defined. A formula using these ratios to determine the non-centrality parameter of the F distribution is deduced. It is shown that in case of more than two groups, equal group numbers does not constitute an optimal design. Two worked examples are presented.
本文包含了一种已知方法的简短推广，该方法用于确定两个以上平行组情况下的样本量。定义了与两组设计中的分配比相对应的“分配比集”。推导了一个使用这些比率来确定F分布非中心参数的公式。结果表明，在两组以上的情况下，相等的组数并不构成最优设计。给出了两个实例。
