TAM (version 1.9-0)

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, ...)

## S3 method for class 'tam.mml':
IRT.residuals(object, ...)
## S3 method for class 'tam.mml':
residuals(object, ...)

## S3 method for class 'tam.mml.2pl':
IRT.residuals(object, ...)
## S3 method for class 'tam.mml.2pl':
residuals(object, ...)

## S3 method for class 'tam.mml.mfr':
IRT.residuals(object, ...)
## S3 method for class 'tam.mml.mfr':
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)