Metaphorical rulers

Rulers — as in [the things we use to measure lengths] — are not only useful, but one can also use them to metaphors to think about. Here are some that I use:

• The Procustean ruler refers the situation when one forcefully changes/adapt the thing that one wants to measure in order to measure it. Background: Procustes is a bandit from Greek mythology. He took people and stretched them or cut off their legs to force them to fit the size of a bed he had. According to wiki the word Procrustean is nowadays used to describe situations where an arbitrary standard is used to measure success, while completely disregarding obvious harm that results from the effort. N.N. Taleb has written a great book that revolves around the concept; but, in general, I am not aware that people actually use it in the wild.
• The Lesbian ruler stands for the inverse concept of the Procustean ruler, i.e.: To adapt the ruler to the measurement. Background: A Lesbian rule was a flexible rule that was used to measure or reproduce irregular curves and apparently used by masons in Lesbos.
• Wittgenstein’s ruler is to the idea that when you measure something, you are not only measuring the measured (your height), but also the measurer itself (the ruler). Here is a good explanation.
• The rubber ruler is similar to the Lesbian ruler, but with a negative connotation in that it will expand or contract depending on context (thus, making comparisons unreliable).