Learn R Programming

⚠️There's a newer version (1.2-0) of this package.Take me there.

ltm (version 0.9-8)

Latent Trait Models under IRT

Description

Analysis of multivariate dichotomous and polytomous data using latent trait models under the Item Response Theory approach. It includes the Rasch, the Two-Parameter Logistic, the Birnbaum's Three-Parameter, the Graded Response, and the Generalized Partial Credit Models.

Copy Link

Version

Install

install.packages('ltm')

Monthly Downloads

6,237

Version

0.9-8

License

GPL (>= 2)

Maintainer

Dimitris Rizopoulos

Last Published

August 17th, 2012

Functions in ltm (0.9-8)

The Law School Admission Test (LSAT), Section VI

Anova method for fitted IRT models

Attitude Towards Abortion

Factor Scores - Ability Estimates

Descriptive Statistics

Residuals for IRT models

Attitude to Science and Technology

Person-Fit Statistics and P-values

Cronbach's alpha

Fit of the model on the margins

Gauss-Hermite Quadrature Points

Latent Trait Models for Item Response Theory Analyses

Women's Mobility

Point-Biserial Correlation

Plot method for fitted IRT models

Area under the Test or Item Information Curves

Goodness of Fit for Rasch Models

Attitude to the Environment

Unidimensionality Check using Modified Parallel Analysis

Fitted Values for IRT model

Graded Response Model - Polytomous IRT

Birnbaum's Three Parameter Model

Summary method for fitted IRT models

Extract Estimated Loadings

Item-Fit Statistics and P-values

Pairwise Associations between Items using a Correlation Coefficient

Factor Scores - Ability Estimates Plot method

testEquatingData

Prepares Data for Test Equating

vcov method for fitted IRT models

Generalized Partial Credit Model - Polytomous IRT

Multiple Choice Items to Binary Responses

Latent Trait Model - Latent Variable Model for Binary Data

Workplace Industrial Relation Survey Data

Descriptive Statistics Plot method

Generate Random Responses Patterns under Dichotomous and Polytomous IRT models