Defer heavily to base rates when entering a domain where you lack experience

In unfamiliar territory, the class distribution should almost entirely govern the forecast.

Why it works

The updating logic behind outside-view thinking is Bayesian: start with the base rate (prior) and update toward the inside view as domain-specific evidence accumulates. In a new domain, that inside-view evidence is thin — you have not yet collected the reliable cues that let expert practitioners adjust usefully. In this situation, weighting the base rate heavily and the inside view lightly is the calibrated move, not a conservative hedge.

How to do it

1. Before operating in a new domain, explicitly rate your experience level: novice, intermediate, or experienced.
2. For novice domains, set a rule: "My inside-view adjustments to the base rate are capped at ±10%."
3. Raise the cap as you accumulate real feedback-corrected experience in the domain.
4. Track when your inside-view adjustments turned out to be well calibrated — this is the signal that the cap can expand.

Evidence

Kahneman & Klein (2009) established that expert intuition is calibrated only when the practitioner has had substantial feedback-corrected experience in a domain with regularities. Without this, inside-view adjustments are more likely to reflect overconfidence than genuine signal. (observational)

The experience threshold for "experienced" is domain-specific and not precisely defined. The cap is a heuristic; the value of 10% is illustrative, not empirically derived.

Sources

• Kahneman & Klein (2009), "Conditions for intuitive expertise," American Psychologist
• Kahneman, D., & Klein, G. (2009). Conditions for intuitive expertise: A failure to disagree. American Psychologist, 64(6), 515-526.

Common mistake

Assuming that enthusiasm and research substitute for domain experience — you can read everything about a domain and still have no calibrated inside-view because you have not yet received feedback.