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KahnemanTemplate
Outside View Planner
Re-estimate a plan by treating it as a member of a reference class instead of a unique case.
15–30 minutes
The plan (inside view estimate)
What does the inside view say in time, cost, success rate?
Reference class - what category does this case belong to?
Broad enough to have ≥5 examples; narrow enough to be relevant.
5+ past examples with actual outcomes
Outcomes, not plans. Median time/cost/success.
Outside-view estimate
What does the reference class predict for this case?
Why might this case beat the reference class?
Must be specific and defensible. «We're smarter» doesn't count.
Output
Updated estimate with explicit reference class and adjustment.
Related concepts
Outside viewEstimate by treating your case as a member of a reference class of similar past cases - not by reasoning from inside your specific story.Planning fallacyWe chronically underestimate how long things will take, how much they will cost, and how much can go wrong.Base rate (and base-rate neglect)The background frequency of something across the relevant population - and the chronic mistake of ignoring it in favour of vivid specifics.Inside viewEstimating a case by reasoning from inside its own story and details - usually too optimistic, usually overconfident.
Read the original book
This part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.