Enumerate scenarios and their probabilities before deciding
Write down each meaningful outcome, assign a probability, and compute the weighted total.
Key takeaways
- What it is: 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."
- Evidence: Backed by observational / correlational evidence.
- Avoid: Listing scenarios until you have covered "everything," ending up with twenty imprecise entries that make probabilities arbitrary and the calculation useless.
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
- 1List the four to six most meaningfully different outcomes of your decision.
- 2Assign a probability to each, ensuring they sum to 100%.
- 3Assign a value (in whatever units matter: money, time, satisfaction) to each outcome.
- 4Multiply each probability by its value and sum — the highest EV option is the baseline recommendation.
What the evidence says
ObservationalScenario 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.
Honest caveat: 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.
IX Coach walks you through scenario mapping before any significant commitment, helping you identify the scenarios that actually matter and avoid both over-engineering and ignoring the alternatives.
Practice this with IX Coach →