当数据抽样于非正态分布时，如未知或混合分布、样本量过小、存在离群点、基于理论分布设计合适的统计检验过于复杂且数学上难以处理等情况，这时基于随机化和重抽样的统计方法可派上用场。(When the sampling data in non normal distribution, such as the unknown or mixed distribution, the sample size is too small, there are outliers, based on the theor