ltm: Latent Trait Models under IRT
Version 1.0-0

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.

Browse man pages Browse package API and functions Browse package files

AuthorDimitris Rizopoulos <d.rizopoulos@erasmusmc.nl>
Date of publication2013-12-20 10:59:19
MaintainerDimitris Rizopoulos <d.rizopoulos@erasmusmc.nl>
LicenseGPL (>= 2)
Version1.0-0
URL http://rwiki.sciviews.org/doku.php?id=packages:cran:ltm
Package repositoryView on CRAN
InstallationInstall the latest version of this package by entering the following in R:
install.packages("ltm")

Man pages

Abortion: Attitude Towards Abortion
anova: Anova method for fitted IRT models
biserial.cor: Point-Biserial Correlation
coef: Extract Estimated Loadings
cronbach.alpha: Cronbach's alpha
descript: Descriptive Statistics
Environment: Attitude to the Environment
factor.scores: Factor Scores - Ability Estimates
fitted: Fitted Values for IRT model
gh: Gauss-Hermite Quadrature Points
GoF: 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
ltm-package: Latent Trait Models for Item Response Theory Analyses
margins: 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: Plot method for fitted IRT models
plot.descript: Descriptive Statistics Plot method
plot.fscores: Factor Scores - Ability Estimates Plot method
rasch: Rasch Model
rcor.test: Pairwise Associations between Items using a Correlation...
residuals: Residuals for IRT models
rmvlogis: Generate Random Responses Patterns under Dichotomous and...
Science: Attitude to Science and Technology
summary: 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: vcov method for fitted IRT models
WIRS: Workplace Industrial Relation Survey Data

Functions

Abortion Man page
EM Source code
Environment Man page
GHpoints Source code
GoF.gpcm Man page Source code
GoF.rasch Man page Source code
IRT.parm Source code
IRT.parm.grm Source code
IRT.parm.ltm Source code
IRT.parm.rasch Source code
IRT.parm.tpm Source code
LSAT Man page
Mobility Man page
Science Man page
WIRS Man page
anova.gpcm Man page Source code
anova.grm Man page Source code
anova.ltm Man page Source code
anova.rasch Man page Source code
anova.tpm Man page Source code
betas.gpcm Source code
betas.grm Source code
betas.ltm Source code
betas.rasch Source code
betas.rasch2 Source code
biserial.cor Man page Source code
cd.tpm Source code
cd.vec Source code
chisq.irt Source code
coef.gpcm Man page Source code
coef.grm Man page Source code
coef.ltm Man page Source code
coef.rasch Man page Source code
coef.tpm Man page Source code
cprobs Source code
crf.GPCM Source code
crf.GPCM2 Source code
cronbach.alpha Man page Source code
cumprobs Source code
descript Man page Source code
factor.scores Man page Source code
factor.scores.gpcm Man page Source code
factor.scores.grm Man page Source code
factor.scores.ltm Man page Source code
factor.scores.rasch Man page Source code
factor.scores.tpm Man page Source code
fd.vec Source code
fitted.gpcm Man page Source code
fitted.grm Man page Source code
fitted.ltm Man page Source code
fitted.rasch Man page Source code
fitted.tpm Man page Source code
fscores.g Source code
fscores.gp Source code
fscores.l Source code
fscores.r Source code
fscores.t Source code
gauher Source code
gh Man page
gpcm Man page Source code
grm Man page Source code
infoGPCM Source code
infoprobs Source code
information Man page Source code
iprobs Source code
item.fit Man page Source code
jacobian Source code
linpred.GPCM Source code
logLik.gpcm Source code
logLik.grm Source code
logLik.ltm Source code
logLik.rasch Source code
logLik.tpm Source code
logLiktpm Source code
loglikgpcm Source code
loglikgrm Source code
loglikltm Source code
ltm Man page Source code
ltm-package Man page
ltm.fit Source code
margins Man page Source code
margins.gpcm Man page Source code
margins.grm Man page Source code
margins.ltm Man page Source code
margins.rasch Man page Source code
margins.tpm Man page Source code
matArrays Source code
matMeans Source code
matSums Source code
matches Source code
mult.choice Man page Source code
observedFreqs Source code
person.fit Man page Source code
plot.aov.gpcm Source code
plot.descript Man page Source code
plot.fscores Man page Source code
plot.gpcm Man page Source code
plot.grm Man page Source code
plot.ltm Man page Source code
plot.rasch Man page Source code
plot.tpm Man page Source code
plot.unidimTest Source code
print.GoF.gpcm Source code
print.GoF.rasch Source code
print.aov.gpcm Source code
print.aov.grm Source code
print.aov.ltm Source code
print.aov.rasch Source code
print.aov.tpm Source code
print.cronbachAlpha Source code
print.descript Source code
print.fscores Source code
print.gpcm Source code
print.grm Source code
print.information Source code
print.itemFit Source code
print.ltm Source code
print.margins.gpcm Source code
print.margins.grm Source code
print.margins.ltm Source code
print.persFit Source code
print.rasch Source code
print.rcor.test Source code
print.summ.gpcm Source code
print.summ.grm Source code
print.summ.ltm Source code
print.summ.rasch Source code
print.summ.tpm Source code
print.tpm Source code
print.unidimTest Source code
probs Source code
rasch Man page Source code
rcor.test Man page Source code
residuals.gpcm Man page Source code
residuals.grm Man page Source code
residuals.ltm Man page Source code
residuals.rasch Man page Source code
residuals.tpm Man page Source code
rmvlogis Man page Source code
rmvordlogis Man page Source code
scoregpcm Source code
scoregpcmSNW Source code
scoregrm Source code
scoreltm Source code
scoretpm Source code
simulate.gpcm Source code
simulate.grm Source code
start.val.gpcm Source code
start.val.grm Source code
start.val.ltm Source code
start.val.rasch Source code
start.val.tpm Source code
summary.gpcm Man page Source code
summary.grm Man page Source code
summary.ltm Man page Source code
summary.rasch Man page Source code
summary.tpm Man page Source code
testEquatingData Man page Source code
thetas.tpm Source code
tpm Man page Source code
unidimTest Man page Source code
vcov.gpcm Man page Source code
vcov.grm Man page Source code
vcov.ltm Man page Source code
vcov.rasch Man page Source code
vcov.tpm Man page Source code

Files

inst
inst/CITATION
inst/NEWS
NAMESPACE
demo
demo/ltm.R
demo/rasch.R
demo/00Index
data
data/Abortion.rda
data/gh.rda
data/WIRS.rda
data/LSAT.rda
data/Science.rda
data/Mobility.rda
data/Environment.rda
R
R/vcov.rasch.R
R/print.summ.ltm.R
R/iprobs.R
R/start.val.rasch.R
R/scoregpcmSNW.R
R/coef.ltm.R
R/residuals.rasch.R
R/jacobian.R
R/residuals.gpcm.R
R/vcov.gpcm.R
R/item.fit.R
R/observedFreqs.R
R/fscores.t.R
R/print.unidimTest.R
R/vcov.ltm.R
R/logLiktpm.R
R/rcor.test.R
R/fscores.r.R
R/probs.R
R/fscores.g.R
R/summary.grm.R
R/descript.R
R/loglikltm.R
R/summary.gpcm.R
R/summary.rasch.R
R/print.information.R
R/GoF.gpcm.R
R/print.tpm.R
R/summary.ltm.R
R/ltm.R
R/plot.ltm.R
R/factor.scores.tpm.R
R/cronbach.alpha.R
R/tpm.R
R/print.summ.grm.R
R/testEquatingData.R
R/infoGPCM.R
R/grm.R
R/simulate.grm.R
R/print.margins.grm.R
R/logLik.grm.R
R/chisq.irt.R
R/anova.ltm.R
R/cumprobs.R
R/vcov.grm.R
R/IRT.parm.ltm.R
R/print.aov.ltm.R
R/coef.grm.R
R/print.gpcm.R
R/margins.grm.R
R/GHpoints.R
R/biserial.cor.R
R/ltm.fit.R
R/print.aov.gpcm.R
R/print.GoF.rasch.R
R/infoprobs.R
R/coef.tpm.R
R/print.fscores.R
R/factor.scores.grm.R
R/matArrays.R
R/print.rasch.R
R/matches.R
R/rmvlogis.R
R/plot.gpcm.R
R/rmvordlogis.R
R/start.val.ltm.R
R/EM.R
R/anova.gpcm.R
R/plot.fscores.R
R/scoregpcm.R
R/plot.grm.R
R/crf.GPCM.R
R/IRT.parm.tpm.R
R/logLik.ltm.R
R/betas.grm.R
R/anova.tpm.R
R/globals.R
R/matMeans.R
R/betas.ltm.R
R/rasch.R
R/GoF.rasch.R
R/print.persFit.R
R/scoretpm.R
R/gpcm.R
R/print.summ.rasch.R
R/scoreltm.R
R/anova.rasch.R
R/coef.rasch.R
R/fitted.grm.R
R/print.grm.R
R/residuals.grm.R
R/start.val.gpcm.R
R/summary.tpm.R
R/plot.rasch.R
R/fitted.rasch.R
R/print.itemFit.R
R/factor.scores.rasch.R
R/print.summ.tpm.R
R/plot.tpm.R
R/crf.GPCM2.R
R/print.aov.tpm.R
R/fd.vec.R
R/logLik.tpm.R
R/plot.aov.gpcm.R
R/simulate.gpcm.R
R/betas.rasch2.R
R/IRT.parm.grm.R
R/loglikgrm.R
R/gauher.R
R/thetas.tpm.R
R/person.fit.R
R/factor.scores.gpcm.R
R/fitted.gpcm.R
R/fitted.tpm.R
R/margins.ltm.R
R/plot.descript.R
R/fscores.gp.R
R/print.rcor.test.R
R/vcov.tpm.R
R/margins.rasch.R
R/print.aov.grm.R
R/print.cronbachAlpha.R
R/cd.tpm.R
R/margins.tpm.R
R/plot.unidimTest.R
R/print.aov.rasch.R
R/logLik.rasch.R
R/margins.gpcm.R
R/loglikgpcm.R
R/anova.grm.R
R/print.margins.gpcm.R
R/cprobs.R
R/print.GoF.gpcm.R
R/fitted.ltm.R
R/print.descript.R
R/linpred.GPCM.R
R/mult.choice.R
R/IRT.parm.R
R/matSums.R
R/betas.gpcm.R
R/cd.vec.R
R/start.val.tpm.R
R/start.val.grm.R
R/print.summ.gpcm.R
R/fscores.l.R
R/margins.R
R/scoregrm.R
R/betas.rasch.R
R/print.margins.ltm.R
R/residuals.ltm.R
R/print.ltm.R
R/factor.scores.ltm.R
R/logLik.gpcm.R
R/factor.scores.R
R/unidimTest.R
R/residuals.tpm.R
R/information.R
R/coef.gpcm.R
R/IRT.parm.rasch.R
MD5
DESCRIPTION
man
man/rasch.Rd
man/gpcm.Rd
man/biserial.cor.Rd
man/anova.Rd
man/rmvlogis.Rd
man/person.fit.Rd
man/WIRS.Rd
man/information.Rd
man/residuals.Rd
man/unidimTest.Rd
man/rcor.test.Rd
man/Environment.Rd
man/tpm.Rd
man/grm.Rd
man/item.fit.Rd
man/cronbach.alpha.Rd
man/ltm-package.Rd
man/LSAT.Rd
man/mult.choice.Rd
man/Science.Rd
man/gh.Rd
man/testEquatingData.Rd
man/vcov.Rd
man/plot.descript.Rd
man/Abortion.Rd
man/factor.scores.Rd
man/fitted.Rd
man/ltm.Rd
man/Mobility.Rd
man/descript.Rd
man/margins.Rd
man/plot.Rd
man/GoF.Rd
man/plot.fscores.Rd
man/coef.Rd
man/summary.Rd
ltm documentation built on May 20, 2017, 3:18 a.m.