Latent Trait Models under IRT
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Documentation for package ‘ltm’ version 1.2-0
- DESCRIPTION file.
- Code demos. Use demo() to run them.
- Package NEWS.
Help Pages
| ltm-package | Latent Trait Models for Item Response Theory Analyses |
| Abortion | Attitude Towards Abortion |
| anova.gpcm | Anova method for fitted IRT models |
| anova.grm | Anova method for fitted IRT models |
| anova.ltm | Anova method for fitted IRT models |
| anova.rasch | Anova method for fitted IRT models |
| anova.tpm | Anova method for fitted IRT models |
| biserial.cor | Point-Biserial Correlation |
| coef.gpcm | Extract Estimated Loadings |
| coef.grm | Extract Estimated Loadings |
| coef.ltm | Extract Estimated Loadings |
| coef.rasch | Extract Estimated Loadings |
| coef.tpm | Extract Estimated Loadings |
| cronbach.alpha | Cronbach's alpha |
| descript | Descriptive Statistics |
| Environment | Attitude to the Environment |
| factor.scores | Factor Scores - Ability Estimates |
| factor.scores.gpcm | Factor Scores - Ability Estimates |
| factor.scores.grm | Factor Scores - Ability Estimates |
| factor.scores.ltm | Factor Scores - Ability Estimates |
| factor.scores.rasch | Factor Scores - Ability Estimates |
| factor.scores.tpm | Factor Scores - Ability Estimates |
| fitted.gpcm | Fitted Values for IRT model |
| fitted.grm | Fitted Values for IRT model |
| fitted.ltm | Fitted Values for IRT model |
| fitted.rasch | Fitted Values for IRT model |
| fitted.tpm | Fitted Values for IRT model |
| gh | Gauss-Hermite Quadrature Points |
| GoF.gpcm | Goodness of Fit for Rasch Models |
| GoF.rasch | Goodness of Fit for Rasch Models |
| gpcm | Generalized Partial Credit Model - Polytomous IRT |
| grm | Graded Response Model - Polytomous IRT |
| information | Area under the Test or Item Information Curves |
| item.fit | Item-Fit Statistics and P-values |
| LSAT | The Law School Admission Test (LSAT), Section VI |
| ltm | Latent Trait Model - Latent Variable Model for Binary Data |
| margins | Fit of the model on the margins |
| margins.gpcm | Fit of the model on the margins |
| margins.grm | Fit of the model on the margins |
| margins.ltm | Fit of the model on the margins |
| margins.rasch | Fit of the model on the margins |
| margins.tpm | Fit of the model on the margins |
| Mobility | Women's Mobility |
| mult.choice | Multiple Choice Items to Binary Responses |
| person.fit | Person-Fit Statistics and P-values |
| plot.descript | Descriptive Statistics Plot method |
| plot.fscores | Factor Scores - Ability Estimates Plot method |
| plot.gpcm | Plot method for fitted IRT models |
| plot.grm | Plot method for fitted IRT models |
| plot.ltm | Plot method for fitted IRT models |
| plot.rasch | Plot method for fitted IRT models |
| plot.tpm | Plot method for fitted IRT models |
| rasch | Rasch Model |
| rcor.test | Pairwise Associations between Items using a Correlation Coefficient |
| residuals.gpcm | Residuals for IRT models |
| residuals.grm | Residuals for IRT models |
| residuals.ltm | Residuals for IRT models |
| residuals.rasch | Residuals for IRT models |
| residuals.tpm | Residuals for IRT models |
| rmvlogis | Generate Random Responses Patterns under Dichotomous and Polytomous IRT models |
| rmvordlogis | Generate Random Responses Patterns under Dichotomous and Polytomous IRT models |
| Science | Attitude to Science and Technology |
| summary.gpcm | Summary method for fitted IRT models |
| summary.grm | Summary method for fitted IRT models |
| summary.ltm | Summary method for fitted IRT models |
| summary.rasch | Summary method for fitted IRT models |
| summary.tpm | Summary method for fitted IRT models |
| testEquatingData | Prepares Data for Test Equating |
| tpm | Birnbaum's Three Parameter Model |
| unidimTest | Unidimensionality Check using Modified Parallel Analysis |
| vcov.gpcm | vcov method for fitted IRT models |
| vcov.grm | vcov method for fitted IRT models |
| vcov.ltm | vcov method for fitted IRT models |
| vcov.rasch | vcov method for fitted IRT models |
| vcov.tpm | vcov method for fitted IRT models |
| WIRS | Workplace Industrial Relation Survey Data |