在最简单最普通的实验中,都有一个单一的目变量(I)和一个单一的应变量(D)。研究假设是 I 引出 D(零假设为 I 不引出 D)。不必将 I 对 D 的影响视为因果性的,尽管通常在实验中确实如此。首要的目标是排除 I 以外的任何变量影响 D 的可能性。凡能达到这一目标的设计均 In the simplest and most common experiment, there is a single head variable (I) and a single dependent variable (D). The research hypothesis is that I leads to D (zero is assumed to be I does not lead to D). It is not necessary to consider the effect of I on D as causal, although this is usually true in experiments. The primary goal is to rule out the possibility that any variable other than I affects D. All can achieve this goal design