抽样规模确定的目标及影响因素

在从总体抽取样本的过程中，抽取多大规模的样本比较合适，这在抽样方案设计之时就必须要给出明确的规定。样本容量确定的目标体现在：一要保证应有的抽样估计精度和检验效率；二要提高对抽样估计结果的概率把握程度；三要尽可能减小机会损失和调查费用。为了实现这些目标，在确定抽样规模时需要系统地兼顾调查对象内部的变异程度、总体分布是否确知、概率把握程度的要求、样本抽取的实现方式、数据的测量水准等因素。

On the Goal and its Factors of Sampling Size Determination

In sampling,the proper sample size must be clearly defined in making a plan.The objectives of sample size determination are: to ensure estimation accuracy and test efficacy;to better draw the statistic map;and to minimize opportunity losses and sampling cost.Therefore,such factors must be taken into account in determining sample size as follow: internal variability of investigated population;statistic distribution of population;sampling with replacement or without replacement;data measuring scale.