Goodhart's Law

When a measure becomes a target, it stops being a good measure.

Why it matters

People will improve the number itself, often in ways that do nothing for what it was meant to show.

How to use it

  • Pair each target with a metric that would reveal gaming.
  • Do not tie pay to one score.
  • Look at what people say and do, as well as the number.

Example

If bonuses depend on NPS, staff may ask customers for a 10 while real satisfaction stays the same.

Go deeper: Growth.Design: NPS surveys