Balanced linear models with fixed effects are taught in undergraduate programs of all universities. These occur in experimental designs such as one-way and two-way Anova, randomized complete block designs (RCBD) and split plot designs. The distributional theory for sums of squares in fixed effects models can be taught using the simplest form of Cochran's Theorem. The contribution provided here allows for an easy extension of the distributional theory to corresponding models with random effects. The main tool used is a simple result on noncentral chi-square distribution overlooked in textbooks at undergraduate and graduate levels.
翻译:所有大学的本科生课程都教授具有固定效果的平衡线性模型,这些模型出现在单向和双向新星、随机整块设计(RCBD)和分割图设计等实验性设计中。固定效果模型中方数的分配理论可以使用Cochran理论的最简单形式来教授。这里提供的材料使得分配理论很容易地扩展到具有随机效果的相应模型。使用的主要工具是本科生和研究生教科书中忽略的非中央奇基平方分布的简单结果。