Decision journal
a structured record of decisions that captures not just what was decided but why, including the reasoning, expected outcomes, and review dates, designed to preserve the actual decision-making process before hindsight bias can contaminate memory
Why This Is a Definition
This definition clearly establishes the term 'decision journal' by naming it, stating its genus (structured record of decisions), and providing its differentia (capturing what was decided, why, reasoning, expected outcomes, review dates) that distinguishes it from mere changelogs or outcome-only records. It specifically addresses the cognitive bias problem of hindsight contamination and explains why this particular form of record is valuable.
Source Lessons
Capture decisions and their reasoning
Record not just what you decided but why — because your future self will rewrite the reasoning after the fact, and you will never notice it happening.
Record your calibration over time
A log of predictions and outcomes shows you exactly where your perception is off.
Well-calibrated perception is a competitive advantage
The ability to see clearly — not optimistically, not pessimistically, but accurately — is rarer and more valuable than most technical skills. Calibrated perception compounds into better decisions, and better decisions compound into better outcomes at every timescale.
Externalize decisions not just information
The most valuable thing to capture is why you chose what you chose. Decisions decay faster than facts — and unlike facts, they cannot be reconstructed after the outcome is known.