What does it mean that calibration is domain-specific?

Being well-calibrated in one area does not transfer automatically to others.

Example: A senior engineer who accurately estimates software project timelines within two weeks consistently gets blindsided by home renovation budgets, investment returns, and how long it takes to learn a new language. Her calibration — hard-won through thousands of shipping cycles — lives inside the domain where she built it. Outside that domain, she's as overconfident as anyone else.

Try this: Pick three domains where you make predictions: your professional work, a hobby, and personal finance. For each, write down five predictions with confidence levels (e.g., '80% confident this will ship by Friday'). Track outcomes over two weeks. Compare your calibration across domains. You will almost certainly find that one domain is dramatically better calibrated than the others.