A new class of designs is introduced for both estimating the variance components of nested factors and testing hypotheses about those variance components. These designs are flexible, and can be chosen so that the degrees of freedom are more evenly spread among the factors than they are in balanced nested designs. The variances of the estimators are smaller than those in stair nested designs of comparable size. The mean squares used in the estimation process are mutually independent, which avoids some of the problems with staggered nested designs.

中文翻译：

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估计具有随机效应的嵌套因子方差成分的稀疏设计

引入了一类新的设计，既可以估计嵌套因子的方差分量，也可以测试关于那些方差分量的假设。这些设计是灵活的，并且可以进行选择，以使自由度比平衡嵌套设计中的因素更均匀地分布在各个因素之间。估计器的方差小于可比较尺寸的楼梯嵌套设计中的方差。估计过程中使用的均方是相互独立的，这避免了交错嵌套设计的某些问题。