有几个标准一>检测异常值。最简单的，如 Chauvenet判据时，使用来自样本计算出的平均值和标准偏差确定一个正常范围的值。此范围以外的任何值被认为是一个局外人。

There are several criteria for detecting outliers. The simplest ones, like Chauvenet's criterion, use the mean and standard deviation calculated from the sample to determine a "normal" range for values. Any value outside of this range is deemed an outlier.

等标准的格拉布的测试并的迪克森的Q检验并可以给出比Chauvenet的，例如更好的结果。

Other criterions are Grubb's test and Dixon's Q test and may give better results than Chauvenet's for example if the sample comes from a skew distribution.