There are several categories of mistake:
- Typo-grade human error:
- Low consequence: who cares
- High consequence: our systems should not allow a typo to have high consequence
- Serious mistake on something they should be able to do
- First time: make sure they learn from it
- Second time: warning
- Third time: performance consequences
- Serious mistake on a stretch assignment: expected. Make sure they learn from it.
It’s very rare for people to make serious mistakes, because most people are cautious and get feedback before committing to a mistake.