What the title says. I know there's a word but can't remember it.
To explain in more detail, I'm trying to state that while the variable is quantitative, the quantity is not referring to an objectively measurable concept. For example something like "happiness" - I can say that happiness is variable linear on an integer scale from 1 to 10, but that does not prevent someone else to define it as logarithmic on a real scale between 0 and 1.
I'm then looking for an adjective to say that: "happiness is a/an ... variable".
I've tried non-parametric, non-unitary, non-measurable, but they all mean something different.