1993 年 20 巻 2 号 p. 35-47
When quantitative data are obtained by sample surveys, we usually estimate a population variance as well as a population mean. It is well known that an unbiased estimator for a population variance is usually used, if a sample is taken under simple random sampling with replacement. However, it is rare that the suitable estimators for other sampling methods are utilized in the actual surveys. These problems arise from misunderstanding about the sampling methods or lack of knowledge of the estimators. In this paper, we investigate the effects of the improper use of estimators on the estimation of a population variance.