Seven deadly sins:
1- Making a measure into a target will mean it’s no use any more (Goodhart’s Law). People play the scoreboard, not the game
2- Any proxy measure of your outcome will take over as your de facto purpose (I call this Deming’s Law)
3- Many measurements are not repeatable or reproducible (measure the same again, get different results)
4- Averages and percentages mean nothing without understanding the impact of the range
5- Binary comparison (two points of data e.g. year-to-year) are meaningless
6- Failure to understand statistics leads to meddling rather than understanding real signals — responding to annual variation as if it’s a surprise!
7- Measures change their meaning from one part of the organisation to another (transduction)
And then, we try to measure multiple things with a single measure (we use budgets — one number — to resource to target, for fiscal control, and to estimate)
Instead, look for measures of purpose — ask the customer:
· Did we do what you needed? Is your life better?
· What could be better next time?
This is self-correcting; if you treat them like a statistic, you’ll know!
What’s your favourite bad measure? What have I missed?