Enumerate scenarios and their probabilities before deciding

Write down each meaningful outcome, assign a probability, and compute the weighted total.

Why it works

The human mind defaults to imagining one future — usually the intended outcome — rather than a distribution. Writing out scenarios with explicit probabilities forces engagement with alternatives that would otherwise be invisible. Each scenario also makes the decision decomposable: you can examine whether your probability estimates are defensible rather than just trusting a gut feeling about "how it will go."

How to do it

1. List the four to six most meaningfully different outcomes of your decision.
2. Assign a probability to each, ensuring they sum to 100%.
3. Assign a value (in whatever units matter: money, time, satisfaction) to each outcome.
4. Multiply each probability by its value and sum — the highest EV option is the baseline recommendation.

Evidence

Scenario planning and explicit probability elicitation are established components of structured decision analysis, which has been shown to outperform unaided intuition in complex multi-attribute decisions. (observational)

Formal decision analysis evidence is strongest in high-stakes organizational settings; its benefit in everyday personal decisions is plausible but less directly studied.

Common mistake

Listing scenarios until you have covered "everything," ending up with twenty imprecise entries that make probabilities arbitrary and the calculation useless.