Project
A decision journal, run for a month
Twenty decisions logged over four weeks, each with a probability attached, then scored against what actually happened. The cheapest instrument that exists for finding out whether your judgement is any good.
- Fix the template. Date, the decision, options considered, what you expect to happen, confidence as a percentage, what would prove you wrong, and the date you will check. Seven fields, one screen.
- Log the ordinary ones too. Hiring, prioritisation, an architecture call, whether to escalate. Twenty in four weeks is roughly one a day, not just the dramatic ones.
- Commit a number every time. "Likely" is unfalsifiable; 70% is not. Force the percentage even when it feels arbitrary — especially then.
- Record the conditions. Time pressure, who was in the room, what you did not know. The patterns in your misses usually live here rather than in the reasoning.
- Score at four weeks. Bucket predictions by confidence — the 60s, 70s, 80s, 90s — and check how often each bucket was right. A Brier score if you want one number for it.
- Name one bias with evidence. Overconfident about your own team's delivery, anchored on the first estimate, over-weighting the loudest voice. One pattern, two examples, one change you will make.
Scope guard: the scored review is the project. A journal without it is a diary and teaches nothing.