Mind · Inference
BaseRateInclude
Outside view over inside view
Definition
Mechanism
Prior probability anchor. Fix the reference class and its base rate before examining the specific case, then adjust for case-specific evidence. Vividness is not evidence. Evidence that places the case in a different reference class changes the prior by changing the class — a reclassification, not an adjustment.
Preconditions
- A reference class with a base rate — measured, or estimated and labelled as such
- Specific case evidence
Postconditions
- Probability estimate adjusted towards mean
Invariants
- The reference class and its base rate are fixed before the case is examined.
- The prior states its source; the posterior states the evidence that moved it.
- A change of reference class is recorded as one, with the new base rate.
Risks
Failure modes
Reference Class Tennis
cherry-picking a favourable class.
Stale prior
the class is right and its rate is out of date.
Relationships
Root pattern: builds on nothing in this library.
Used by
References
Mathematically rigorous belief revision
Aligning subjective confidence with objective frequency
Accounting for silent failures in data
Reference