规定了一种方法，用于将总体差异的平均值与零或任何其他预先指定的值进行比较。它可用于确定两种处理之间的差异，其中“处理”应被广泛理解，例如，作为涉及的试验方法、测量仪器或实验室，并适用于一系列差异可被视为一系列独立随机项目，且差异分布为正态或近似正态的条件。如果分布偏离正态分布，只要样本量足够大（100或更多），它仍然有效。

A method is specified for comparing the mean of a population of differences with zero or any other preassigned value. It may be applied to establish a difference between two treatments, where "treatment" should be understood in a wide sense, e.g. as a test method, measuring instrument or laboratory involved, and is applicable under the conditions that the series of differences can be considered as a series of independent random items and the distribution of the differences is normal or approximately normal. If the distribution deviates from the normal, it remains valid provided the sample size is sufficiently large (100 and more).