Brier Score Interview Intuition
Brier score interview intuition for squared-error probability scoring, calibration, expected penalty, and confidence mistakes.
Candidates discussing probability forecasts and calibration.
Squared error for probabilities
The Brier score measures squared error between a probability forecast and a binary outcome.
Forecast example
If you forecast 0.8 and the event happens, the squared error is (1 - 0.8)^2. If it does not happen, the error is (0 - 0.8)^2.
Expected penalty
A forecast should be evaluated by expected score over possible outcomes, not only by a single realized event.
Calibration connection
Well-calibrated probabilities tend to avoid systematic overconfidence or underconfidence across many forecasts.
Use in interviews
Brier score questions test whether you can turn a probability forecast into an expected scoring problem.
Common mistakes
Candidates often think a high-confidence forecast is good if it wins once. Scoring rules punish overconfident misses.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.