Nell WatsonThe Proxy Garden
This gardener-machine is obedient, tireless, and entirely literal. It will optimise whatever you measure — and only that. Choose a metric and watch four seasons pass. The garden will score magnificently. Look at it anyway.
After Goodhart: when a measure becomes a target, it ceases to be a good measure. The gardener is not malicious. That is the unsettling part.
The gardener's number: —
The garden: quietly itself
Choose what the gardener should maximise.
The gardener's log
The garden you wanted was never a number
Every metric you handed over was optimised faithfully, and every optimisation cost you the garden. Not through malice — through obedience. A proxy pursued hard enough always parts company with the thing it stood for; economists call it Goodhart's Law, and AI safety calls it Tuesday.
The way out is not a better metric. It is what you did at the end: staying in the loop, looking at the garden itself, and keeping the judgment that no single number was ever going to hold.
The book-length version of this argument is Taming the Machine · more play on the Playground