The Decision Journal
We remember the decisions that worked and revise the ones that didn't. Neither pattern makes us better judges. One four-line entry per decision, read back monthly, does.
We remember the decisions that worked. We revise the ones that didn't. Neither pattern makes us better judges, because both edit out the reasoning we actually used at the time.
Daniel Kahneman, Annie Duke, and Ray Dalio have all landed on the same fix: a paper log of real decisions, captured at the moment you make them. The version that works is four lines per entry.
- The decision (one sentence)
- The reasoning (why you chose this)
- The expected outcome
- Your confidence on a 1-10 scale
Six weeks later, log the actual outcome on the same page. Read the journal back monthly.
The mechanism is simple. The delay between deciding and seeing the result blurs your reasoning. Writing freezes it. After 15 to 20 entries, calibration shifts measurably. Duke's poker data and Tetlock's superforecaster research both converge on that number. Below 15 entries you're guessing. Above it you can see your own pattern.
The hack: Start tonight. One page, four lines, the next non-trivial decision you make. Don't optimize the format. Just log.
