SAMPLE-SIZE DETERMINATION FOR STEP-DOWN MULTIPLE TEST PROCEDURES - ORTHOGONAL CONTRASTS AND COMPARISONS WITH A CONTROL
SAMPLE-SIZE DETERMINATION FOR STEP-DOWN MULTIPLE TEST PROCEDURES - ORTHOGONAL CONTRASTS AND COMPARISONS WITH A CONTROL
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DOI：
10.1016/0378-3758(91)90042-d
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发表时间：
1991-03-01
影响因子：
0.9
通讯作者：
TAMHANE, AC
中科院分区：
文献类型：
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作者：
HAYTER, AJ;TAMHANE, AC
我们解决的问题，逐步下降的多重比较程序（MCP）的两个nonhierarchical家庭-正交对比和比较，以保证其权力的规定要求的样本量确定。相应的单步MCP的结果作为特殊情况获得。数值计算的样本大小，以确保指定的功率需求进行了单侧比较，在选定的情况下与控制问题。这些计算表明，对于所考虑的情况，通过使用米勒（1966年，第103页）的逐步降低的MCP，可以在总样本量中节省约10%至20%。85-86），而不是Dunnett（1955）的单步MCP。正如预期的那样，随着处理次数的增加，与对照组相比，节省的百分比增加。在确定每个MCP的最小总样本量以保证指定的功率要求的过程中，我们还确定了该样本量在处理组和对照组之间的最佳分配。我们发现Dunnett（1955）推荐的平方根分配规则为两个MCP的最优分配提供了一个合理的近似。
We address the problem of sample size determination for step-down multiple comparison procedures (MCP's) for two nonhierarchical families - orthogonal contrasts and comparisons with a control, in order to guarantee a specified requirement on their power. The results for the corresponding single-step MCP's are obtained as special cases.Numerical calculations of the sample sizes to guarantee a specified power requirement are carried out for the one-sided comparisons with a control problem in selected cases. These calculations show that for the cases considered, about 10% to 20% savings can be achieved in the total sample size by using the step-down MCP of Miller (1966, pp. 85-86) instead of the single-step MCP of Dunnett (1955). The percentage savings increase, as expected, with the number of treatments being compared with the control.In the process of determining the smallest total sample size for each MCP to guarantee the specified power requirement, we also determine the optimum allocation of this sample size among the treatments and the control. We find that the square root allocation rule recommended by Dunnett (1955) provides a reasonable approximation to the optimum allocation for both the MCP's.