catSurv (version 1.3.0)

fisherInf: Fisher's Information

Description

Calculates the expected value of the observed information of the likelihood evaluated at the input value \(\theta\).

Usage

fisherInf(catObj, theta, item)

Arguments

catObj

An object of class Cat

theta

A numeric or an integer indicating the potential value for \(\theta\)

item

An integer indicating the index of the question item

Value

The function fisherInf returns a numeric of the expected value of the observed information of the likelihood evaluated at the input value \(\theta\).

Details

For the dichotomous case, this Fisher's information is equivalent to the observed information.

See Also

fisherTestInfo, obsInf, selectItem

Examples

# NOT RUN {
## Loading ltm Cat object
data(ltm_cat)

## Store example answers
setAnswers(ltm_cat) <- c(1,0,1,0,1, rep(NA, 35))

## Fisher's information for different items, at ability parameter of 1
fisherInf(ltm_cat, theta = 1, item = 10)
fisherInf(ltm_cat, theta = 1, item = 20)


# }