multi stage sampling的意思|示意

Methods Subjects were collected from community population by stratified multi-stage cluster sampling method. The data gathered from case investigation and serological detection.

方法对社区人群采用多阶段分层整群随机抽样方法抽取研究对象，进行个案调查和血清学检测。

Methods A total of 7482 residents aged 15-69 selected in representative 30 counties through multi-stage random sampling from Zhejiang Province were surveyed by using questionnaire.

方法采用多阶段随机抽样的方法，在浙江省有代表性的30个县区，对7482名年龄在15～69岁的居民进行面对面问卷调查。

RESEARCH METHODThe stratified multi-stage cluster random sampling method was used in the survey.

研究方法本研究采用分层整群随机抽样方法进行抽样。

We give the approximation formulas of the variance of the sample ratio estimator for a population mean and its asymptotically non-biased estimator in multi-stage sampling.

讨论多阶段抽样比率估计及其样本量选择的问题，给出了比率估计抽样均方误差的近似公式及其渐近无偏估计的公式。

Method A multi-stage stratified cluster sampling survey on health condition of 14486 residents was taken in 2007.

方法：采用多阶段分层整群抽样方法，对2007年居民家庭健康状况入户调查，共调查14 486人。

Methods. The survey was conducted according to multi-stage stratified cluster sampling method.

方法：分阶段分层整群随机抽样调查。