likelihood_interval: Likelihood Interval

In likelihood.model: Likelihood-Based Statistical Inference in the Fisherian Tradition

Likelihood Interval

Description

Computes the likelihood interval for a parameter: LI(k) = {theta : R(theta) >= 1/k} = {theta : S(theta) >= -log(k)}

Usage

likelihood_interval(x, ...)

## S3 method for class 'fisher_mle'
likelihood_interval(x, data, model, k = 8, param = NULL, ...)

Arguments

x	A fisher_mle object
...	Additional arguments passed to optimization
data	Data frame used for likelihood computation
model	The likelihood model used for fitting
k	Likelihood ratio cutoff (default 8, giving 1/8 interval)
param	Index or name of parameter for profile interval (NULL for all)

Details

Unlike confidence intervals, likelihood intervals make no probability statements about the parameter. They simply identify the set of parameter values that are well-supported by the data.

Common choices for k:

• k = 8: 1/8 likelihood interval (~95% CI equivalent)

• k = 15: 1/15 likelihood interval (~99% CI equivalent)

• k = 32: 1/32 likelihood interval (~99.9% CI equivalent)

For multivariate parameters, specify param to get a profile likelihood interval for that parameter (profiling over the others).

Value

Matrix with lower and upper bounds for each parameter

likelihood.model documentation built on March 19, 2026, 9:07 a.m.