fisherInf {catSurv} R Documentation

## 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

### Details

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

### Value

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

### Note

This function is to allow users to access the internal functions of the package. During item selection, all calculations are done in compiled C++ code.

### Author(s)

Haley Acevedo, Ryden Butler, Josh W. Cutler, Matt Malis, Jacob M. Montgomery, Tom Wilkinson, Erin Rossiter, Min Hee Seo, Alex Weil

fisherTestInfo, obsInf, selectItem

### Examples

## Loading ltm Cat object
data(ltm_cat)