Tell me about a time you were confident about the cause of a problem and turned out to be wrong. How did you find out, and what did you do next?
Follow-up probes
- What evidence first made you suspicious of your own diagnosis?
- What would have happened if you'd been wrong for another month?
- What do you do differently now when you feel that certain?
Why this works
Confident misdiagnosis is where problem-solving actually fails — not for lack of analysis, but analysis aimed at defending a belief. The "how did you find out" clause forces a concrete account instead of a philosophy of humility, and shows whether the candidate tests assumptions or protects them.
What good looks like
A specific incident with a real cost, told without blame; the signal that broke the assumption named precisely; and a changed habit since — disconfirming checks run earlier, confidence treated as a cue to verify rather than a reason to stop.