stratified_simple_random_sampling

1.This paper introduced several methods about the concrete strength inspection: the sampling method given by the present specification; simple random sampling without replacement; stratified sampling.
具体介绍了砼强度检测抽样的几种方法：现行规程抽样法；简单随机抽样法；分层抽样法。
dict.yoduao.com
2.Stratified sampling can reduce the sampling error associated with simple random samples.
分层抽样可以减少由简单随机抽样造成的抽样误差。
dict.yoduao.com
3.During the course of cluster sample verification, systematic sampling and stratified sampling "s accuracy are prior to simple random sampling" s.
群样本检验中，系统抽样群样本检验和分层随机抽样群样本检验的效果优于简单随机抽样群样本检验。
dict.yoduao.com