Strive for range, not accuracy!
Ask Questions like:
- Are our chances above or below 50%?
- If above (below) better than 90% (worse than10%)?
- If below 90% (above 10%) then above or below 70% (30%)?
Donít ask "What is the longest time this activity could take?"
- The inevitable answer will be "Forever"!
Deal with the Impact scale the same way
- Except note that it is a ratio scale, not linear