stratified random sampling

基本解釋

In each year of the study, 500–600 health facilities providing the BPHS were selected by stratified random sampling in 29 provinces of Afghanistan.
研究過程中，每年從阿富汗的29個省份中分層隨機(jī)取樣選擇提供基礎(chǔ)系列醫(yī)療服務(wù)的500到600個醫(yī)療機(jī)構(gòu)。
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.
方法采用整群分層隨機(jī)抽樣的方法，對吉林市某醫(yī)學(xué)院校及非醫(yī)學(xué)高校的在校大學(xué)生進(jìn)行問卷調(diào)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.
采取分層隨機(jī)取樣方式選取大連4所大學(xué)在校生作為研討對象，抽取不同年級、性別的在校生共460名，最后篩選出有效問卷共406份。