是从被研究的全部对象中抽取部分对象进行的调查的统称。它与普查、报表制度等全面调查不同,属于非全面调查。在抽样调查中,被研究对象的全体称为总体、母体、全及总体或统计总体;从总体中抽取的部分对象所组成的群体称为样本、样本总体或抽样总体:组成总体或样本的最小单位称为个案、总体单位、统计单位或调查单位。个案可以是一个人、一个工厂、一个学校或一个家庭等具体单位。 It is a general term for surveys that take part of the objects from all the subjects under study. It is different from the general survey such as the census and the reporting system. It belongs to the non-comprehensive investigation. In the sample survey, the whole study object is called the overall, maternal, total and overall population; part of the population extracted from the population consisting of groups called the sample, sample population or sample population: the total composition or the smallest sample A unit is called a case, an overall unit, a statistical unit, or an investigation unit. Cases can be a single person, a factory, a school or a family and other specific units.