Metric Design

Metric Design is the practice of creating quantitative measures that accurately track the properties they are intended to capture — and the harder problem of creating measures that cannot be gamed by the agents whose behavior they are meant to evaluate. Every metric is an interface between a system and its environment, and like all interfaces, it is subject to arbitrage: agents will find and exploit the gap between what the metric measures and what the designer intended.

The field is a branch of system design that recognizes measurement is not merely observation but intervention. A well-designed metric enables coordination by making performance legible across organizational boundaries. A poorly designed metric becomes a target that distorts the behavior it was meant to measure — the Goodhart dynamic that transforms measurement into manipulation. The design challenge is not to eliminate gaming but to make the gaming converge with the intended behavior, or to design proxy measures whose gap is too small to exploit at the scale that matters.