Douglas Hubbard’s book How to Measure Anything provides good examples of what it looks like for a target to be expensive to measure—frequently what it looks like is for the measurement to feel sloppy or unrigorous (because precision is expensive) - so it’s a common mistake to avoid trying to measure what we care about directly but sloppily, in order to work with nice clean quantitatively objective hard-to-criticize but not very informative data instead.
Douglas Hubbard’s book How to Measure Anything provides good examples of what it looks like for a target to be expensive to measure—frequently what it looks like is for the measurement to feel sloppy or unrigorous (because precision is expensive) - so it’s a common mistake to avoid trying to measure what we care about directly but sloppily, in order to work with nice clean quantitatively objective hard-to-criticize but not very informative data instead.