Guides ยท Math
Bayes Theorem Intuition Basics
Update beliefs with simple Bayes
This guide builds intuition for Bayes' theorem: start with base rates, weigh how likely evidence is under different hypotheses, and update your belief using simple ratio thinking.
- bayes theorem
- base rates
- likelihood
- posterior
- probability
Start with base rates
Note how common the thing is before new evidence arrives.
Consider likelihoods
Ask how likely the evidence is if the hypothesis is true vs false.
Update simply
Posterior ? prior ? likelihood; use ratio thinking rather than exact formulas when possible.
Watch common traps
Beware ignoring base rates, over-trusting tests with false positives, and mixing up P(A|B) with P(B|A).