论文标题
评估模型选择在生态学中的重要性
Assessing the Significance of Model Selection in Ecology
论文作者
论文摘要
模型选择是许多生态研究的关键部分,Akaike的信息标准是最常用的技术。通常,许多候选模型被定义为先验,并根据其预期的样本外观进行排名。但是,模型选择仅评估模型的相对性能,正如最近论文所指出的那样,使用模型选择的大量生态论文不会评估“最佳”模型的绝对拟合度。在本文中,有人认为,仅评估“最佳”模型的绝对拟合度还不够远。这是因为在模型选择下似乎表现良好的模型在绝对拟合度的度量下也可能表现出色,即使没有预测值。提出了一个模型选择置换测试,该测试评估了“最佳”模型的模型选择统计量可能仅偶然地发生的概率,同时考虑了模型之间的依赖关系。有人认为,该测试应始终在进行正式模型选择之前进行。该测试在意大利北部的IBEX和挪威的野生驯鹿的两个真实人口建模实例上进行了证明。
Model Selection is a key part of many ecological studies, with Akaike's Information Criterion the most commonly used technique. Typically, a number of candidate models are defined a priori and ranked according to their expected out-of-sample performance. Model selection, however, only assesses the relative performance of the models and, as pointed out in a recent paper, a large proportion of ecology papers that use model selection do not assess the absolute fit of the `best' model. In this paper, it is argued that assessing the absolute fit of the `best' model alone does not go far enough. This is because a model that appears to perform well under model selection is also likely to appear to perform well under measures of absolute fit, even when there is no predictive value. A model selection permutation test is proposed that assesses the probability that the model selection statistic of the `best' model could have occurred by chance alone, whilst taking account of dependencies between the models. It is argued that this test should always be performed before formal model selection takes place. The test is demonstrated on two real population modelling examples of ibex in northern Italy and wild reindeer in Norway.