plot.tif

An object produced by function <code>tif</code>

When <code>add=T</code>, the TIF is added to a plot,
  otherwise a new plot is started. Default is F.

The main title of the plot, given that
  <code>add=F</code>.

main

The colour of the TIF curve. Default is 1 for
  black. Use <code>co=NA</code> to plot each TIF in a different
  colour.


  Useful for plotting test information functions. The
  <code>x</code> argument of <code>tif</code> should better be left out
  unless something special is required.


models

Provides a simple common interface to the estimation of item
parameters in IRT models for binary responses with three different programs
(ICL, BILOG-MG, and ltm, and a variety of functions useful with IRT models.

plot.tif: A plot method for test information functions

Description

Usage

Arguments

See Also

Examples