医学显性致死试验平均死胎率比较的统计分析

负二项分布方法可用作比较显性致死试验中平均死胎率的差异 ,本文对传统的负二项分布方法进行了描述 ,同时提出两种非参数方法 ,且就以上的方法的不足进行了比较 ,例子显示利用文中的一种非参数方法—L法更为合理     

Some Methods for Estimation in a Negative-Binomial Model

To clarify the advantage of using the quasilikelihood method, lack of robustness of the maximum likelihood method was demonstrated for the negative-binomial model. Efficiency calculations of the method of moments and the pseudolikelihood method in the estimation of extra-Poisson parameters in a negative-binomial model were carried out. Especially when the overdispersion parameter is small, both methods are relatively highly efficient and the pseudolikelihood estimate is more efficient than the method of moments estimate. Two examples of the quasilikelihood analyses of count data with overdispersion are given. The bootstrap method also is applied to the data to illustrate the advantage of the method of moments or pseudolikelihood method in the estimation of the standard errors of the mean parameter estimates under the negative-binomial model.