expectedObsInf {catSurv}

Expected Observed Information

Description

Calculates the expected information, which is the observed information attained from a specific response set times the probability of that profile occurring.

Usage

expectedObsInf(catObj, item)

Arguments

catObj

An object of class Cat

item

An integer indicating the index of the question item

Value

The function expectedObsInf returns a numeric value of the expected information. **Not implemented for three parameter model for binary data.**

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

See Also

estimateSE,obsInf, probability, selectItem

Examples

## Loading ltm Cat object
data(ltm_cat)

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

## Expected observed information for different items
expectedObsInf(ltm_cat, item = 10)
expectedObsInf(ltm_cat, item = 20)