生态学整合分析中两种常用效应值的实例应用比较

整合分析(meta-analysis)是对同一主题下多个独立实验结果进行综合的统计学方法,被认为是到目前为止最好的数量综合方法,其统计量为效应值,反应比(InR)和Hedges'd值是生态学应用中最常用的两个效应值。以综合植物生理生态学指标对大气CO₂浓度倍增响应为实例,比较这两种效应值的不同之处。采用两种效应值指标会对同一个生理生态指标产生不同的总效应值大小,有时甚至会改变效应值的方向;InR相对Hedges'd更易产生正效应值;Hedges'd较InR可拉大不同生理生态指标之间总效应值的差异;Hedges'd具有正负效应对称性,而InR却具有正负效应的不对称性。

Comparison of two effect sizes of meta-analysis commonly used in ecology

Meta-analysis is a statistical method to summarize the different individual studies under the same subject。 InR and Hedges'd are the two effect sizes that are most commonly used in ecology.They are compared in analyzing response of plant ecophysilogical variables to high CO₂ concentration.For the same variable, two effect size might result in different overall effect size and even occasionally change its direction.LnR was apt to lead to positive effect.The range of overall effect sizes of 24 variables given by Hedges'd was wider than that by InR.Effect size given by LnR was asymmetry, while that by Hedges'd symmetry.