How do you interpret a Bayes factor?
hardAnswer
- — ratio of marginal likelihoods → posterior odds = BF × prior odds.
- Jeffreys scale: BF > 10 strong evidence for , > 100 decisive; BF < 1/10 flip.
- Unlike p-values, symmetric — can support .
- Weakness: hypersensitive to prior choice for nuisance parameters (Lindley's paradox).
- Alternative in practice: LOO-CV, WAIC, PSIS-LOO for predictive model comparison.
Check yourself — multiple choice
- Random
- Ratio of marginal likelihoods; Jeffreys scale > 10 strong, > 100 decisive; symmetric ; prior-sensitive → also use LOO-CV / WAIC
- Same as p-value
- Not useful
Bayes factor: ; symmetric; prior-sensitive.
#bayesian
Practise Statistics Fundamentals
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