"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
随机实验是因果推理的黄金标准,但它们并不总是可行的。
你沾沾自喜,别人乐于喜欢你;你攻击你周围的某个人,其他的人哈哈大笑;但倘若你解剖你自己的灵魂,所有的人就会嗷嗷叫。——作者原注
To understand the meaning of a sentence, we must consider the speaker's intention and the context of the utterance.