CDM (version 4.8-0)

IRT.factor.scores: S3 Methods for Extracting Factor Scores (Person Classifications)

Description

This S3 method extracts factor scores or skill classifications.

Usage

IRT.factor.scores(object, ...)

## S3 method for class 'din':
IRT.factor.scores(object, type="MLE", \dots)

## S3 method for class 'gdina':
IRT.factor.scores(object, type="MLE", \dots)

## S3 method for class 'mcdina':
IRT.factor.scores(object, type="MLE", \dots)

## S3 method for class 'gdm':
IRT.factor.scores(object, type="EAP", \dots)

## S3 method for class 'slca':
IRT.factor.scores(object, type="MLE", \dots)

Arguments

object

Object of classes din, gdina, mcdina, gdm or

type

Type of estimated factor score. This can be "MLE", "MAP" or "EAP". The type EAP cannot be used for objects of class slca.

...

More arguments to be passed.

Value

• A matrix or a vector with classified scores.

See Also

For extracting the individual likelihood or the individual posterior see IRT.likelihood or IRT.posterior.

Examples

#############################################################################
# EXAMPLE 1: Extracting factor scores in the DINA model
#############################################################################

data(sim.dina)
data(sim.qmatrix)
# estimate model with only few iterations
mod1 <- din(sim.dina, sim.qmatrix, maxit=10)
summary(mod1)
# MLE
fsc1a <- IRT.factor.scores(mod1 )
# MAP
fsc1b <- IRT.factor.scores(mod1 , type="MAP")
# EAP
fsc1c <- IRT.factor.scores(mod1 , type="EAP")
# compare classification for skill 1
stats::xtabs( ~ fsc1a[,1] + fsc1b[,1] )
graphics::boxplot( fsc1c[,1] ~ fsc1a[,1] )