A risky shortcut works and the person who chose it is praised as decisive. The same shortcut fails a week later and suddenly seems obviously foolish. What changed: the quality of the reasoning, or our knowledge of the result?
This is the question behind outcome bias. It is useful whenever we review a decision made under uncertainty, from a team project to an everyday personal choice.
Reconstruct the moment before the result
List what the decision-maker knew, what remained uncertain and which alternatives were realistically available. Avoid adding information that became clear only afterwards. A fact discovered on Friday could not guide a choice made on Monday.
In their 1988 research on outcome bias, Jonathan Baron and John Hershey examined how knowledge of outcomes can affect evaluations of decisions. The concept does not imply that outcomes are irrelevant; it asks us to be more precise about what we are judging.
Try changing only the ending
Imagine an illustrative project manager selecting a supplier after a proportionate review of quality, capacity and references. An unexpected disruption later prevents delivery. Would you call the original process careless if the disruption had not occurred?
Now consider the reverse: a supplier chosen without checking a known critical requirement happens to deliver successfully. The favourable result does not make the omitted check a sound practice.
Keep responsibility in the picture
Separating process from outcome is not a way to excuse harm. The consequences still matter to the people affected, and they may reveal information that improves future decisions. A fair review can acknowledge damage, examine preventable mistakes and avoid pretending that every bad result was predictable.
Ask whether the decision-maker sought relevant information, considered affected people and responded appropriately to uncertainty. These questions are more useful than declaring a person wise or foolish based on one result.
Write two conclusions instead of one verdict
First, describe the process: what was reasonable, missing or unclear at the time. Second, describe the outcome and what it teaches now. Keep the two connected without collapsing them into one judgement.
A brief decision note written beforehand can help with later review. Record the choice, reasons, uncertainties and a point for reassessment. The aim is not to eliminate luck from life. It is to learn without allowing hindsight to rewrite the evidence we actually had.