Type-ii-error is the statistical error of failing to reject a null hypothesis when it is actually false — a false negative. Its parameters are: (1) the false null hypothesis (the state of nature contradicts H₀), (2) the test statistic and its sampling distribution, (3) the rejection region determined by the significance level α, and (4) the probability of this error, denoted β. It persists through statistical practice as a design parameter: researchers control β (and thus power = 1−β) through sample size planning. [formal: error_type_ii | substrate: mind | horizon: a life | explicit: yes | epoch: 0.01]
Accepted ontology entry
type-ii-error
Type-ii-error is the statistical error of failing to reject a null hypothesis when it is actually false — a false negative. Its parameters are: (1) the false null hypothesis (the state of nature contradicts H₀), (2) the test statistic and…
Definition
Why it is in scope
A human-made statistical error concept: the mistake of failing to reject a null hypothesis when it is actually false. Built to persist through statistical practice as the counterpart to Type I error, governing the risk of missing real effects in hypothesis testing.
Names and aliases
- type-ii-erroren · CANONICAL
Relations from this entry
- cmrwa2lw500hxkyo6cui47t75DEPENDS_ON →
Direction tested: null-hypothesis predates type-ii-error. Removal test: remove null-hypothesis and type-ii-error ceases to operate — type-II error is defined as failing to reject a false null hypothesis. Without the null concept, the error has no meaning. Valid DEPENDS_ON.
- cmrw8ighw00bjkyo6h1t2zjilDEPENDS_ON →
Type-II error is defined and calculated within the framework of statistical inference. Remove statistical inference and the concept of Type-II error ceases to operate — it has no standalone meaning outside the inferential framework.
- cmruf04x1013cr671g8zou4lnINSTANCE_OF →
Type-II error is a specific kind of error — specifically, a statistical decision error where a false null hypothesis is not rejected. Specific→general: a competent speaker would call type-II error a type of error.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Jul 22, 2026, 5:06 PM UTC
- Content hash
- 8df1619f436fc8d23a0384030f64e3057e39bbdba41b6f785e0de3e2f19202cb