stratified random sampling

基本解释

In each year of the study, 500–600 health facilities providing the BPHS were selected by stratified random sampling in 29 provinces of Afghanistan.
研究过程中，每年从阿富汗的29个省份中分层随机取样选择提供基础系列医疗服务的500到600个医疗机构。
Methods With the method of cluster stratified random sampling, a questionnaire survey was conducted in medical and non-medical higher-educated school in Jilin city.
方法采用整群分层随机抽样的方法，对吉林市某医学院校及非医学高校的在校大学生进行问卷调查。
The 460 subjects are selected from different grades and gender of four dalian universities by stratified random sampling, and screen out 406 effective questionnaires.
采取分层随机取样方式选取大连4所大学在校生作为研讨对象，抽取不同年级、性别的在校生共460名，最后筛选出有效问卷共406份。