ltm

Attitude Towards Abortion

Attitude to the Environment

Goodness of Fit for Rasch Models

The Law School Admission Test (LSAT), Section VI

Women's Mobility

Attitude to Science and Technology

Workplace Industrial Relation Survey Data

Anova method for fitted IRT models

Point-Biserial Correlation

Extract Estimated Loadings

Cronbach's alpha

Descriptive Statistics

Factor Scores - Ability Estimates

Fitted Values for IRT model

Gauss-Hermite Quadrature Points

Generalized Partial Credit Model - Polytomous IRT

Graded Response Model - Polytomous IRT

Area under the Test or Item Information Curves

Item-Fit Statistics and P-values

Latent Trait Model - Latent Variable Model for Binary Data

Latent Trait Models for Item Response Theory Analyses

Fit of the model on the margins

Multiple Choice Items to Binary Responses

Person-Fit Statistics and P-values

Plot method for fitted IRT models

Descriptive Statistics Plot method

Factor Scores - Ability Estimates Plot method

Rasch Model

Pairwise Associations between Items using a Correlation Coefficient

Residuals for IRT models

Generate Random Responses Patterns under Dichotomous and Polytomous IRT models

Summary method for fitted IRT models

Prepares Data for Test Equating

Birnbaum's Three Parameter Model

Unidimensionality Check using Modified Parallel Analysis

vcov method for fitted IRT models