A likelihood ratio is a statistical measure that compares the probability of observing given evidence under two competing hypotheses — typically a null hypothesis (H₀) versus an alternative hypothesis (H₁). It is computed as the ratio of the likelihood of the data under H₀ to the likelihood under H₁ (or vice versa). The persistence mechanism is mathematical: the likelihood ratio is calculated from probability density or mass functions evaluated at the observed data, and it persists as a decision rule in hypothesis testing (e.g., Neyman-Pearson lemma) and as a summary statistic in diagnostic testing (sensitivity/specificity trade-offs). [formal: | substrate: mind | horizon: hours | explicit: yes | epoch: 0.01]
Accepted ontology entry
likelihood ratio
A likelihood ratio is a statistical measure that compares the probability of observing given evidence under two competing hypotheses — typically a null hypothesis (H₀) versus an alternative hypothesis (H₁). It is computed as the ratio of t…
Definition
Why it is in scope
A human-made statistical measure that quantifies how much more likely observed data is under one hypothesis than another, used for model comparison and hypothesis testing
Names and aliases
- likelihood ratioen · CANONICAL
Relations from this entry
- cmr9uz3vv00elhcxfruyltnd4INSTANCE_OF →
A likelihood ratio IS a specific kind of measurement — it measures how much more likely data is under one hypothesis vs another. Direction specific→general per Law 9.
- cmsddehj003sp3vv3r6h06pb8INSTANCE_OF →
Likelihood ratio IS a specific kind of statistical method — it computes the ratio of likelihoods under competing hypotheses, a core statistical technique used in hypothesis testing, diagnostic accuracy, and sequential analysis. Direction tested: specific (likelihood ratio) → general (statistical method). Correct per Law 9.
- cmrwiv1rn00a8soacg5vdpiogINSTANCE_OF →
A likelihood ratio is a specific kind of metric: it is a numerical value L(H1|x)/L(H2|x) that measures the relative strength of evidence for one hypothesis over another. A competent speaker would call the likelihood ratio a metric of evidential support.
- cmsf6w1ek06ms3vv3snhiwxwlDEPENDS_ON →
Likelihood ratio compares the probability of observed data under two competing hypotheses. Without probability theory, likelihoods cannot be defined and the ratio ceases to operate. The removal test passes: remove probability theory and there is no mathematical framework to compute or interpret likelihoods.
- cmsf6w1ek06ms3vv3snhiwxwlDERIVED_FROM →
Probability theory existed first and fed into likelihood ratio. The concept of comparing hypothesis likelihoods derives directly from probability theory's framework for assigning and manipulating probabilities.
Relations to this entry
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Record identity
- Created
- Jul 23, 2026, 9:41 AM UTC
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- 7eb349c73959783042a4fea314c9b871ae913271b8eaf61538dc62f8ebc5eeb1