Good metrics leave room for judgement

What gets measured often improves. It can also become distorted.

A metric compresses reality so that we can see a pattern. The compression is useful, but something is always left out. Trouble begins when the number stops being a signal and becomes the definition of success.

Good operators respect data without outsourcing judgement to it. They ask how the metric was constructed, what behaviour it encourages, and what important experience it cannot see.

Numbers help us notice. They do not relieve us of the responsibility to think.