Map the Assumptions Behind a Decision

Use this first principles decision worksheet when a plan feels built on unexamined beliefs. State the decision, note at least one observation, then write the assumptions that connect what you know to what you want to do. Give each assumption an impact and confidence level and name a way to check it. The review order is a simple sorting aid, not a probability or a verdict: observations and confidence are your own judgments, and the tool does not verify them.

How to use Assumption Ledger

1. Write the decision in a sentence and record something you directly observed; add more observations if they matter.
2. For each assumption, write the claim and a concrete way to check it. Select how much it would matter if wrong and how confident you currently feel.
3. Build the review plan to see which low-confidence, high-impact assumption to check first. Edit the worksheet to revise it, or download the plan as Markdown.