rule of thumb

昨天的IT英语考试试卷，翻译题中遇到一短语，rule of thumb，这啥？拇指规则？

今天在看课件时，又遇到了rule of thumb，立即警觉起来，于是“词霸+google+wiki”了一下这个短语。

原来在中文里也有“拇指规则”这种说法，意思就是——凭感觉的方法; 单凭经验的方法。

wiki对它有详细的解释，包括它的由来。

The earliest citation comes from Sir William Hope’s The Compleat Fencing-Master, second edition, 1692, page 157: “What he doth, he doth by rule of thumb, and not by art.” The term is thought to originate with wood workers who used the length of their thumbs rather than rulers for measuring things, cementing its modern use as an imprecise yet reliable and convenient standard.

大概意思就是说，木工工人测量物体时，依据的是他们拇指的长度，而不是尺子什么的。这就是一种经验，不一定非常准确，但是却可靠而方便。