A matrix of binary responses to a test, with persons as rows and
items as columns.

resp

The item (column number in <code>resp</code>) to plot.

item

Produces a plot of the empirical response function (proportion of correct 
responses at each possible sum score).

models

A collection of functions useful in learning and practicing IRT,
which can be combined into larger programs. Provides basic CTT analysis,
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), ability estimation (MLE, BME, EAP, WLE, plausible
values), item and person fit statistics, scaling methods (MM, MS, Stocking-Lord,
and the complete Hebaera method), and a rich array of parametric and
non-parametric (kernel) plots. Estimates and plots Haberman's interaction model
when all items are dichotomously scored.

Ivailo Partchev

erf: Plot empirical response function

Description

Usage

Arguments

Value

Examples