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ltm (version 1.1-1)

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.

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Version

Install

install.packages('ltm')

Monthly Downloads

8,147

Version

1.1-1

License

GPL (>= 2)

Issues

1

Pull Requests

0

Stars

30

Forks

12

Maintainer

Dimitris Rizopoulos

Last Published

April 17th, 2018

Functions in ltm (1.1-1)

coef

Extract Estimated Loadings
grm

Graded Response Model - Polytomous IRT
item.fit

Item-Fit Statistics and P-values
anova

Anova method for fitted IRT models
Mobility

Women's Mobility
information

Area under the Test or Item Information Curves
plot descript

Descriptive Statistics Plot method
summary

Summary method for fitted IRT models
rmvlogis

Generate Random Responses Patterns under Dichotomous and Polytomous IRT models
cronbach.alpha

Cronbach's alpha
descript

Descriptive Statistics
plot IRT

Plot method for fitted IRT models
margins

Fit of the model on the margins
Science

Attitude to Science and Technology
ltm-package

Latent Trait Models for Item Response Theory Analyses
ltm

Latent Trait Model - Latent Variable Model for Binary Data
rcor.test

Pairwise Associations between Items using a Correlation Coefficient
residuals

Residuals for IRT models
factor.scores

Factor Scores - Ability Estimates
fitted

Fitted Values for IRT model
unidimTest

Unidimensionality Check using Modified Parallel Analysis
vcov

vcov method for fitted IRT models
mult.choice

Multiple Choice Items to Binary Responses
person.fit

Person-Fit Statistics and P-values
gh

Gauss-Hermite Quadrature Points
Abortion

Attitude Towards Abortion
LSAT

The Law School Admission Test (LSAT), Section VI
GoF

Goodness of Fit for Rasch Models
gpcm

Generalized Partial Credit Model - Polytomous IRT
biserial.cor

Point-Biserial Correlation
plot fscores

Factor Scores - Ability Estimates Plot method
WIRS

Workplace Industrial Relation Survey Data
testEquatingData

Prepares Data for Test Equating
Environment

Attitude to the Environment
rasch

Rasch Model
tpm

Birnbaum's Three Parameter Model