Thinking method · Kahneman, Thinking, Fast and Slow
The outside view
Estimating from what usually happens in cases like this, before reasoning from your own. Estimating how long something will take, or whether a plan will work.
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Estimating from what usually happens in cases like this, before reasoning from your own.
The steps
- Define the reference class: what category of thing is this?
- Ask what usually happens to things in that class. Find real numbers if you can.
- Start your estimate there.
- Only then adjust for what is genuinely different about your case — and adjust less than you want to.
When to use it
Estimating how long something will take, or whether a plan will work.
What it will not do
A badly chosen reference class gives a confidently wrong number. Say which class you used.
Where it comes from: Kahneman, Thinking, Fast and Slow. Described in our own words.
The module it belongs to
- Decision Thinking — Make better decisions under uncertainty