itm.mlteqc {equateMultiple}

Extract Item Parameters

Description

itm is a generic function which extracts a data frame containing the item parameters of multiple forms being equated in the original scale and the item parameters converted to the scale of the base form.

Usage

## S3 method for class 'mlteqc'
itm(x, ...)

Arguments

x

object of the class mlteqc returned by function multiec

...

further arguments passed to or from other methods.

Value

A data frame containing item names (Item), item parameters of all the forms (e.g. T1, ..., T3), and item parameters of all the forms converted in the scale of the base form (e.g. T3.as.T1).

Author(s)

Michela Battauz

See Also

multiec

Examples

data(est2pl)
# prepare the data
mods <- modIRT(coef = est2pl$coef, var = est2pl$var, display = FALSE)
# Estimation of the equating coefficients with the multiple item response function method
eqIRF <- multiec(mods = mods, base = 1, method = "irf")

# extract item parameters
itm(eqIRF)