what is rule of thumb

The phrase "rule of thumb" refers to an approximate method for doing something based on practical experience rather than theory. The exact origin of the phrase is uncertain, but it can be traced back to the 17th century. There are many theories about the origin of the phrase, including that it was used to refer to using the tip of the thumb as a unit of measurement. However, some have also suggested that the phrase was associated with domestic abuse in the 1970s, which led to efforts to discourage its use. Despite this, the phrase continues to be used in everyday language to refer to a general principle or heuristic guideline that provides simplified advice or some basic rule-set regarding a particular subject or course of action. While rules of thumb can be useful as general guidelines, they may be too oversimplified in many situations, leading to underestimating or overestimating an individuals needs.