itemplot

a computed model object of class
  <code>ExploratoryClass</code> or <code>ConfirmatoryClass</code>

object

a single numeric value indicating which item
  to plot

item

plot type to use, information
  (<code>'info'</code>), information contours
  <code>('infocontour')</code>, or item trace lines
  (<code>'trace'</code>)

type

the degrees argument to be used if there
  are exactly two factors. See <code><a href="/link/iteminfo?package=mirt&version=0.4.0" rd-options="" data-mini-rdoc="mirt::iteminfo">iteminfo</a></code> for
  more detail

degrees

additional arguments to be passed to lattice

<code>itemplot</code> displays various item based IRT plots.

plot

Analysis of dichotomous and polytomous response data using
        latent trait models under the Item Response Theory paradigm.
        Includes univariate and multivariate one-, two-, three-, and
        four-parameter logistic models, graded response models,
        generalized partial credit models, nominal models, multiple
        choice models, and multivariate partially-compensatory models.
        These can be used in an exploratory or confirmatory manner with
        optional user defined linear constraints. Exploratory models
        can be estimated via quadrature or stochastic methods, a
        generalized confirmatory bi-factor analysis is included, and
        confirmatory models can be fit with a Metropolis-Hastings
        Robbins-Monro algorithm which can include polynomial or product
        constructed latent traits. Additionally, multiple group
        analysis may be performed for unidimensional or
        multidimensional item response models for detecting
        differential item functioning.

itemplot: Displays item surface and information plots

Description

Usage

Arguments

Examples