This principle helps explain why people behave differently from what pure logic would predict.
More quotesFirst, the measure observes.
Waiting time indicates service. Test scores indicate learning. Clicks indicate attention.
Then somebody attaches a target.
The service sends an automatic reply and calls the wait finished. Teaching narrows towards the exam. Headlines become more agitated because agitation produces clicks.
Finally, the number improves.
Everyone congratulates the system while the outcome it once represented quietly deteriorates.
This is Goodhart’s law as a lifecycle. A proxy can reveal something useful when nobody has reason to manipulate it. Give it money, status or punishment and people discover the gap between the definition and reality. That discovery is called gaming when done crudely and performance management when supplied with a dashboard.
Multiple measures help when their weaknesses differ. Direct observation helps more. Sudden improvement at the exact boundary of a definition deserves curiosity, especially when customers, pupils or patients report that nothing improved.
Judgement remains necessary, which is unpopular because judgement leaves fingerprints. A metric lets responsibility hide inside arithmetic. But the choice of number, target and threshold was judgement too; it merely happened earlier and escaped notice.
When the indicator becomes immaculate and the lived result becomes awful, inspect the lived result. Sit with the customer. Watch the process from beginning to end. Record the behaviour just outside the measured boundary. The dashboard can remain open while this happens; it simply no longer gets the only vote.