Log the decision before the outcome

Write what you decided, why, and what you expect — before you know how it turns out.

Why it works

Hindsight bias overwrites the memory of your pre-decision reasoning with knowledge of what actually happened, making bad decisions look smart in retrospect (if lucky) and good decisions look naive (if unlucky). Writing the reasoning down before the outcome creates an immutable external record that the bias cannot reconstruct. This is the foundational move of decision journaling: without it, you have no ground truth to review.

How to do it

1. For any significant decision, write: the decision, the date, your reasoning in 2–4 sentences, and your expected outcome.
2. Assign a rough confidence level (e.g., "70% confident this will succeed in the next six months").
3. Note what information you do not have that you wish you did.
4. Close the entry and do not revisit it until the outcome arrives.

Evidence

Pre-outcome recording directly counteracts hindsight bias, which is one of the most replicated biases in the judgment literature. The mechanism is simple and structural: you cannot rewrite a written record the way you can rewrite a memory. Fischhoff’s original experiments showed that once people know an outcome, they systematically misremember having expected it — exactly the memory distortion a pre-outcome written record makes impossible. (mechanistic)

Pre-logging prevents hindsight rewriting; whether the logging habit translates into better future decisions depends on the quality of the review and whether lessons are actually extracted and applied.

Sources

• Fischhoff (1975), "Hindsight ≠ Foresight", Journal of Experimental Psychology — establishes the bias that pre-logging counteracts
• Fischhoff, B. (1975). Hindsight ≠ foresight: The effect of outcome knowledge on judgment under uncertainty. Journal of Experimental Psychology: Human Perception and Performance, 1(3), 288–299.
• Roese, N. J., & Vohs, K. D. (2012). Hindsight bias. Perspectives on Psychological Science, 7(5), 411–426.

Common mistake

Logging only the conclusion ("I decided to hire her") without the reasoning, which leaves no material to review when the outcome arrives. The reasoning — not the decision — is what you’re preserving.