EI-201c · Module 2
Probabilistic Forecasting
3 min read
Point predictions ("Model X will reach GPT-4 performance by Q3") are almost always wrong. Probabilistic forecasts ("There is a 60% chance that at least one open-source model reaches GPT-4 performance on enterprise benchmarks by Q3, and a 25% chance it happens by Q2") are calibratable — meaning you can measure whether your probability estimates match actual outcomes over time. Calibration is the secret weapon of professional forecasting. An analyst whose 70% predictions come true 70% of the time is a reliable source of decision-grade intelligence.
- Express Every Forecast as a Probability Replace "Model X will..." with "There is a [X]% chance that Model X will..." This forces you to think about uncertainty explicitly instead of hiding it behind confident-sounding language. It also gives your consumers a calibrated input for their decision-making.
- Track Your Calibration Log every probabilistic forecast with its probability and the eventual outcome. After 50+ forecasts, plot a calibration curve: do your 60% predictions come true about 60% of the time? Most analysts are overconfident — their 80% predictions come true only 60% of the time. Knowing your calibration bias lets you correct for it.
- Update Probabilities with New Evidence Bayesian updating: when new evidence arrives, adjust your probability estimate. A 40% forecast that new evidence supports becomes 55%. A 70% forecast that contradictory evidence challenges becomes 50%. Communicate updates to your briefing consumers with the reason for the change. Transparency in updating builds trust.