Methods a cluster sample of 499 children was randomly chosen from 6 primary schools in chongqing 方法采用隨機(jī)整群抽樣,對(duì)重慶市城區(qū)6所小學(xué)在讀流動(dòng)兒童449名進(jìn)行問卷調(diào)查。
This paper discusses cluster sampling and stratified cluster sampling in continuous surveys with censuses 摘要本文討論了連續(xù)調(diào)查中應(yīng)用普查方法時(shí)的整群抽樣和分層整群抽樣。
Methods : random cluster sampling method was used . 2763 subjects were studied with a self - reported questionnaire 方法:采用整群隨機(jī)抽樣方法,對(duì)2763名學(xué)生通過自填問卷的方式進(jìn)行了調(diào)查。
Methods cluster sampling method was adopted in this study , and epidemiology characters of emergency injuries in shenzhen city were analyzed 方法采用抽樣方法調(diào)查本市急救中心2001年7月至2002年6月急診傷害就診情況。