R: Plot of Item Parameter Estimates

plot.mlteqc {equateMultiple}

R Documentation

Plot of Item Parameter Estimates

Description

plot method for class mlteqc, which plots item parameter estimates of one form agains the item parameter estimates of the base form before and after conversion.

Usage

## S3 method for class 'mlteqc'
plot(x, form = 2, ask = prod(par("mfcol")) < x$itmp*2 && dev.interactive(), ...)

Arguments

x

an object of the class mlteqc returned by function multiec.

form

test form. It can be specified by name or number.

ask

logical; if TRUE, the user is asked before each plot.

...

further arguments passed to or from other methods.

Author(s)

Michela Battauz

Examples

data(est2pl)
# prepare the data
mods <- modIRT(coef = est2pl$coef, var = est2pl$var, display = FALSE)
# Estimation of the equating coefficients with the multiple mean-mean method
eqMM <- multiec(mods = mods, base = 1, method = "mean-mean")
plot(eqMM, form = "T2")