EstimatedItemDistribution: Estimate the score distribution for an individual item in a...

In CambridgeAssessmentResearch/unimirt: Applications of Unidimensional IRT using the R Package 'mirt'

Estimate the score distribution for an individual item in a "mirt" object.

Description

This function uses the fitted model estimates the percentage of persons that will get each score. If there is no missing data for the item (i.e. all persons have atctually taken the item) then the function will also provide the actual percentages.

Usage

EstimatedItemDistribution(mirtobj, which.item, theta = NULL, qwts = NULL)

Arguments

mirtobj	An estimated IRT model (of class SingleGroupClass) estimated either using mirt or unimirt.
which.item	An integer denoting which item to investigate.
theta	A matrix giving the ability values used in estimation. By default this is extracted directly from mirtobj.
qwts	A vector giving the weight to assign to each ability in thetas. By default this is extracted directly from mirtobj.

Examples

## Not run: 
mirt1=unimirt(mathsdata,"2")
EstimatedItemDistribution(mirt1,1)
EstimatedItemDistribution(mirt1,19)

## End(Not run)

CambridgeAssessmentResearch/unimirt documentation built on June 10, 2025, 6:03 a.m.