显著性检验（significance test）就是事先对总体（随机变量）的参数或总体分布形式做出一个假设，然后利用样本信息来判断这个假设（备择假设）是否合理，即判断总体的真实情况与原假设是否有显著性差异。或者说，显著性检验要判断样本与我们对总体所做的假设之间的差异是纯属机会变异，还是由我们所做的假设与总体真实情况之间不一致所引起的。 显著性检验是针对我们对总体所做的假设做检验，其原理就是“小概率事件实际不可能性原理”来接受或否定假设。
抽样实验会产生抽样误差，对实验资料进行比较分析时，不能仅凭两个结果（平均数或率）的不同就作出结论，而是要进行统计学分析，鉴别出两者差异是抽样误差引起的，还是由特定的实验处理引起的。(The significance test (significance test) is to make a hypothesis on the parameters of the total (random variable) or the overall distribution in advance, and then use the sample information to judge whether the hypothesis is reasonable, that is, to judge whether there is a significant difference between the real situation and the original hypothesis. Or, the difference between the significance test and the assumptions we do on the whole is purely an opportunity variation, or is it caused by the disagreement between the assumptions we do and the overall reality. The significance test is to test the assumptions we do on the whole, and the principle is to accept or deny the hypothesis, "the principle of the actual impossibility of small probability events".　　　　　　Sampling experiments will produce sampling errors. When comparing)