Interpreting Blocks and Random Factors
本文从统计相关性的角度，探讨随机区组设计中能否检验区组效应，比较两种线性混合模型公式的优劣，并提出增强模型清晰度和启发式实用性的建议。
Abstract Can blocks be tested in a randomized blocks design? It is well known that two different formulations of the linear mixed model yield conflicting answers to this question. This article examines the model formulations from the point of view of statistical relevance. Viewing blocking as a device to increase efficiency leads to a hypothesis concerning blocks that is distinct from the hypothesis of no “block main effect.” Relevant tests and interval estimates are reviewed. The merits of the two model formulations are compared, and recommendations are made to enhance the clarity and heuristic usefulness of mixed linear models.