论文标题
具有复杂阻塞结构和网络效应的农业现场实验的设计
Designs with complex blocking structures and network effects for agricultural field experiments
论文作者
论文摘要
我们提出了一种基于模型的新方法，用于构建具有复杂阻塞结构和网络效应的最佳设计，用于在农业场实验中应用。通过网络结构描述了应用于不同图的处理之间的潜在干扰，该网络结构通过邻接矩阵定义。我们考虑在Rothamsted Research进行现场试验，并比较各种不同模型下的最佳设计，包括在这种情况下常用的设计。结果表明，当相邻图上的处理之间存在干扰时，由于图的空间排列，结合网络效应的设计至少比随机的行柱设计至少和效率更高。网络设计的优点是，即使是通过图，我们也可以为不规则的布局构建邻居结构，以解决实验的特定特征。当需要考虑治疗引起的异质性模式时，就会出现对这种设计的需求。忽略网络结构会导致对治疗参数和无效结论的不精确估计。
We propose a novel model-based approach for constructing optimal designs with complex blocking structures and network effects, for application in agricultural field experiments. The potential interference among treatments applied to different plots is described via a network structure, defined via the adjacency matrix. We consider a field trial run at Rothamsted Research and provide a comparison of optimal designs under various different models, including the commonly used designs in such situations. It is shown that when there is interference between treatments on neighbouring plots, due to the spatial arrangement of the plots, designs incorporating network effects are at least as, and often more efficient than, randomised row-column designs. The advantage of network designs is that we can construct the neighbour structure even for an irregular layout by means of a graph to address the particular characteristics of the experiment. The need for such designs arises when it is required to account for treatment-induced patterns of heterogeneity. Ignoring the network structure can lead to imprecise estimates of the treatment parameters and invalid conclusions.
