Equations · equation
Bayes' Theorem
Mathematics · 1763
- Equation
- P(A|B) = P(B|A)·P(A) / P(B)
- Field
- Mathematics
- Named After
- Thomas Bayes · Richard Price
- Year
- 1763
Symbols
P(A|B) belief in A after seeing evidence B · P(B|A) how likely the evidence is if A holds · P(A) belief before the evidence · P(B) how likely the evidence is overall
Significance
How to change your mind, made arithmetic: prior belief times the weight of evidence gives updated belief. Published posthumously by Bayes' friend Price, it now runs spam filters, medical diagnostics, spacecraft navigation — and explains why a positive test for a rare disease is usually a false alarm.
Referenced by
equation
instrument
Open on the Equations shelf — the interactive card, the filters, and everything alongside it.