TAM (version 1.995-0)

IRT.residuals: Residuals in an IRT Model

Description

Defines an S3 method for the computation of observed residual values. The computation of residuals is based on weighted likelihood estimates as person parameters, see tam.wle. IRT.residuals can only be applied for unidimensional IRT models. The methods IRT.residuals and residuals are equivalent.

Usage

IRT.residuals(object, ...)
"IRT.residuals"(object, ...)
"residuals"(object, ...)
"IRT.residuals"(object, ...)
"residuals"(object, ...)
"IRT.residuals"(object, ...)
"residuals"(object, ...)

Arguments

object

Object of class tam.mml, tam.mml.2pl or tam.mml.mfr.

...

Further arguments to be passed

Value

List with following entries

residuals

Residuals

stand_residuals

Standardized residuals

X_exp

Expected value of the item response $X_{pi}$

X_var

Variance of the item response $X_{pi}$

theta

Used person parameter estimate

probs

Expected item response probabilities

See Also

See also the residuals (eRm) or residuals (mirt) functions.

See also predict.tam.mml.

Examples

#############################################################################
# EXAMPLE 1: Residuals data.read
#############################################################################	

library(sirt)
data(data.read,package="sirt")
dat <- data.read

# for Rasch model
mod <- tam.mml( dat )
# extract residuals
res <- IRT.residuals( mod )
str(res)