Gio Wiederhold PDM
8
Establishing causality is risky
•
1.
Is a Volvo a safe car?
2. What causes accidents?
Drivers!
3. Who buys Volvos?
4. Must determine
•
effect of safe drivers
•
percentage of safe drivers overall
•
percentage of safe drivers with Volvos
5. How much of the accident rate is now explained?
The unexplained difference can be attributed to the car.
Careful drivers!
Mined:
Volvos have fewer accidents
