equateMultiple (version 1.1.1)

item.common: Estimates the Item Parameters on a Common Scale

Description

item.common is a generic function which extracts the estimates of the item parameters on the scale of the base form, which is obtained using the item parameter estimates across all forms.

Usage

item.common(x, ...)
# S3 method for mlteqc
item.common(x, ...)

Value

A data frame containing item names (Item), estimated value of the item parameter (Estimate) and its standard error (StdErr).

Arguments

x

object of the class mlteqc returned by function multiec

...

further arguments passed to or from other methods.

Author

Michela Battauz

See Also

itm, 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")

# estimates of the item parameters on the scale of the base form
item.common(eqIRF)