The Effective Sample Size
针对非独立同分布或向量观测数据,提出一种适用于一般线性模型的有效样本量定义,并用于贝叶斯模型选择中默认先验分布的尺度设定。
Model selection procedures often depend explicitly on the sample size n of the experiment. One example is the Bayesian information criterion (BIC) criterion and another is the use of Zellner–Siow priors in Bayesian model selection. Sample size is well-defined if one has i.i.d real observations, but is not well-defined for vector observations or in non-i.i.d. settings; extensions of critera such as BIC to such settings thus requires a definition of effective sample size that applies also in such cases. A definition of effective sample size that applies to fairly general linear models is proposed and illustrated in a variety of situations. The definition is also used to propose a suitable ‘scale’ for default proper priors for Bayesian model selection.