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sirt

Supplementary Item Response Theory Models

If you use sirt and have suggestions for improvement or have found bugs, please email me at robitzsch@leibniz-ipn.de. Please always provide a minimal dataset, necessary to demonstrate the problem, a minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and all necessary information on the used librarys, the R version, and the OS it is run on, perhaps a sessionInfo().

CRAN version

The official version of sirt is hosted on CRAN and may be found here. The CRAN version can be installed from within R using:

utils::install.packages("sirt")

GitHub version

The version hosted here is the development version of sirt. The GitHub version can be installed using devtools as:

devtools::install_github("alexanderrobitzsch/sirt")

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Version

Install

install.packages('sirt')

Monthly Downloads

11,682

Version

4.2-133

License

GPL (>= 2)

Issues

Pull Requests

Stars

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Maintainer

Alexander Robitzsch

Last Published

September 27th, 2025

Functions in sirt (4.2-133)

brm-Methods

Functions for the Beta Item Response Model
Q3

Estimation of the \(Q_3\) Statistic (Yen, 1984)
IRT.mle

Person Parameter Estimation
btm

Extended Bradley-Terry Model
R2noharm.jackknife

Jackknife Estimation of NOHARM Analysis
R2conquest

Running ConQuest From Within R
Q3.testlet

\(Q_3\) Statistic of Yen (1984) for Testlets
automatic.recode

Automatic Method of Finding Keys in a Dataset with Raw Item Responses
R2noharm.EAP

EAP Factor Score Estimation
R2noharm

Estimation of a NOHARM Analysis from within R
conf.detect

Confirmatory DETECT and polyDETECT Analysis
data.activity.itempars

Item Parameters Cultural Activities
categorize

Categorize and Decategorize Variables in a Data Frame
cfa_meas_inv

Estimation of a Unidimensional Factor Model under Full and Partial Measurement Invariance
data.eid

Examples with Datasets from Eid and Schmidt (2014)
data.bs

Datasets from Borg and Staufenbiel (2007)
class.accuracy.rasch

Classification Accuracy in the Rasch Model
ccov.np

Nonparametric Estimation of Conditional Covariances of Item Pairs
data.befki

BEFKI Dataset (Schroeders, Schipolowski, & Wilhelm, 2015)
data.big5

Dataset Big 5 from qgraph Package
data.mixed1

Dataset with Mixed Dichotomous and Polytomous Item Responses
data.inv4gr

Dataset for Invariance Testing with 4 Groups
data.ml

Multilevel Datasets
data.lsem

Datasets for Local Structural Equation Models / Moderated Factor Analysis
data.long

Longitudinal Dataset
data.pirlsmissing

Dataset from PIRLS Study with Missing Responses
data.liking.science

Dataset 'Liking For Science'
data.raw1

Dataset with Raw Item Responses
data.ratings

Rating Datasets
data.pisa2006Read

Dataset PISA 2006 Reading
data.g308

C-Test Datasets
data.ess2005

Dataset European Social Survey 2005
data.pw

Datasets for Pairwise Comparisons
data.pisaRead

Dataset PISA Reading
data.math

Dataset Mathematics
data.noharm

Datasets for NOHARM Analysis
data.pars1.rasch

Item Parameters for Three Studies Obtained by 1PL and 2PL Estimation
data.mcdonald

Some Datasets from McDonald's Test Theory Book
data.pisaMath

Dataset PISA Mathematics
data.pisaPars

Item Parameters from Two PISA Studies
dif.logistic.regression

Differential Item Functioning using Logistic Regression Analysis
data.read

Dataset Reading
data.reck

Datasets from Reckase' Book Multidimensional Item Response Theory
dif.strata.variance

Stratified DIF Variance
data.timss

Dataset TIMSS Mathematics
data.wide2long

Converting a Data Frame from Wide Format in a Long Format
data.sirt

Some Example Datasets for the sirt Package
data.timss07.G8.RUS

TIMSS 2007 Grade 8 Mathematics and Science Russia
data.trees

Dataset Used in Stoyan, Pommerening and Wuensche (2018)
detect.index

Calculation of the DETECT and polyDETECT Index
equating.rasch.jackknife

Jackknife Equating Error in Generalized Logistic Rasch Model
eigenvalues.manymatrices

Computation of Eigenvalues of Many Symmetric Matrices
dif.variance

DIF Variance
dirichlet.simul

Simulation of a Dirichlet Distributed Vectors
f1d.irt

Functional Unidimensional Item Response Model
expl.detect

Exploratory DETECT Analysis
dmlavaan

Comparing Regression Parameters of Different lavaan Models Fitted to the Same Dataset
dirichlet.mle

Maximum Likelihood Estimation of the Dirichlet Distribution
fit.isop

Fitting the ISOP and ADISOP Model for Frequency Tables
equating.rasch

Equating in the Generalized Logistic Rasch Model
fuzdiscr

Estimation of a Discrete Distribution for Fuzzy Data (Data in Belief Function Framework)
fuzcluster

Clustering for Continuous Fuzzy Data
isop

Fit Unidimensional ISOP and ADISOP Model to Dichotomous and Polytomous Item Responses
isop.test

Testing the ISOP Model
invariance.alignment

Alignment Procedure for Linking under Approximate Invariance
gom.jml

Grade of Membership Model (Joint Maximum Likelihood Estimation)
gom.em

Discrete (Rasch) Grade of Membership Model
latent.regression.em.raschtype

Latent Regression Model for the Generalized Logistic Item Response Model and the Linear Model for Normal Responses
greenyang.reliability

Reliability for Dichotomous Item Response Data Using the Method of Green and Yang (2009)
isop.scoring

Scoring Persons and Items in the ISOP Model
lq_fit

Fit of a \(L_q\) Regression Model
linking.haebara

Haebara Linking of the 2PL Model for Multiple Studies
locpolycor

Local Modeling of Thresholds and Polychoric Correlations
linking_2groups

Linking Two Groups
lavaan2mirt

Converting a lavaan Model into a mirt Model
lc.2raters

Latent Class Model for Two Exchangeable Raters and One Item
linking.robust

Robust Linking of Item Intercepts
likelihood.adjustment

Adjustment and Approximation of Individual Likelihood Functions
linking.haberman

Linking in the 2PL/Generalized Partial Credit Model
lsdm

Least Squares Distance Method of Cognitive Validation
matrixfunctions.sirt

Some Matrix Functions
mcmc.2pno.ml

Random Item Response Model / Multilevel IRT Model
mcmc.3pno.testlet

3PNO Testlet Model
lsem.test

Test a Local Structural Equation Model Based on Bootstrap
mcmc.2pnoh

MCMC Estimation of the Hierarchical IRT Model for Criterion-Referenced Measurement
marginal.truescore.reliability

True-Score Reliability for Dichotomous Data
mcmc.list.descriptives

Computation of Descriptive Statistics for a mcmc.list Object
mcmc.2pno

MCMC Estimation of the Two-Parameter Normal Ogive Item Response Model
lsem.estimate

Local Structural Equation Models (LSEM)
lsem.permutationTest

Permutation Test for a Local Structural Equation Model
md.pattern.sirt

Response Pattern in a Binary Matrix
monoreg.rowwise

Monotone Regression for Rows or Columns in a Matrix
mirt.wrapper

Some Functions for Wrapping with the mirt Package
mcmclist2coda

Write Coda File from an Object of Class mcmc.list
modelfit.sirt

Assessing Model Fit and Local Dependence by Comparing Observed and Expected Item Pair Correlations
mle.pcm.group

Maximum Likelihood Estimation of Person or Group Parameters in the Generalized Partial Credit Model
mgsem

Estimation of Multiple-Group Structural Equation Models
mcmc_Rhat

Computation of the Rhat Statistic from a Single MCMC Chain
mirt.specify.partable

Specify or modify a Parameter Table in mirt
mcmc_coef

Some Methods for Objects of Class mcmc.list
np.dich

Nonparametric Estimation of Item Response Functions
pcm.fit

Item and Person Fit Statistics for the Partial Credit Model
person.parameter.rasch.copula

Person Parameter Estimation of the Rasch Copula Model (Braeken, 2011)
personfit.stat

Person Fit Statistics for the Rasch Model
pgenlogis

Calculation of Probabilities and Moments for the Generalized Logistic Item Response Model
parmsummary_extend

Includes Confidence Interval in Parameter Summary Table
pbivnorm2

Cumulative Function for the Bivariate Normal Distribution
pcm.conversion

Conversion of the Parameterization of the Partial Credit Model
noharm.sirt

NOHARM Model in R
nedelsky-methods

Functions for the Nedelsky Model
plausible.value.imputation.raschtype

Plausible Value Imputation in Generalized Logistic Item Response Model
polychoric2

Polychoric Correlation
prob.guttman

Probabilistic Guttman Model
plot.np.dich

Plot Method for Object of Class np.dich
rasch.copula2

Multidimensional IRT Copula Model
plot.mcmc.sirt

Plot Function for Objects of Class mcmc.sirt
rasch.evm.pcm

Estimation of the Partial Credit Model using the Eigenvector Method
prmse.subscores.scales

Proportional Reduction of Mean Squared Error (PRMSE) for Subscale Scores
qmc.nodes

Calculation of Quasi Monte Carlo Integration Points
prior_model_parse

Parsing a Prior Model
rasch.jml.jackknife1

Jackknifing the IRT Model Estimated by Joint Maximum Likelihood (JML)
rasch.mirtlc

Multidimensional Latent Class 1PL and 2PL Model
rasch.jml

Joint Maximum Likelihood (JML) Estimation of the Rasch Model
rasch.mml2

Estimation of the Generalized Logistic Item Response Model, Ramsay's Quotient Model, Nonparametric Item Response Model, Pseudo-Likelihood Estimation and a Missing Data Item Response Model
rasch.pairwise.itemcluster

Pairwise Estimation of the Rasch Model for Locally Dependent Items
rasch.jml.biascorr

Bias Correction of Item Parameters for Joint Maximum Likelihood Estimation in the Rasch model
rasch.va

Estimation of the Rasch Model with Variational Approximation
rasch.prox

PROX Estimation Method for the Rasch Model
rasch.pml3

Pairwise Marginal Likelihood Estimation for the Probit Rasch Model
rasch.pairwise

Pairwise Estimation Method of the Rasch Model
rinvgamma2

Inverse Gamma Distribution in Prior Sample Size Parameterization
rm.sdt

Hierarchical Rater Model Based on Signal Detection Theory (HRM-SDT)
reliability.nonlinearSEM

Estimation of Reliability for Confirmatory Factor Analyses Based on Dichotomous Data
scale_group_means

Scaling of Group Means and Standard Deviations
sim.qm.ramsay

Simulate from Ramsay's Quotient Model
sim.rasch.dep

Simulation of the Rasch Model with Locally Dependent Responses
sia.sirt

Statistical Implicative Analysis (SIA)
rmvn

Simulation of a Multivariate Normal Distribution with Exact Moments
resp_groupwise

Creates Group-Wise Item Response Dataset
rm.facets

Rater Facets Models with Item/Rater Intercepts and Slopes
stratified.cronbach.alpha

Stratified Cronbach's Alpha
sirt-package

tools:::Rd_package_title("sirt")
sim.raschtype

Simulate from Generalized Logistic Item Response Model
tam2mirt

Converting a fitted TAM Object into a mirt Object
summary.mcmc.sirt

Summary Method for Objects of Class mcmc.sirt
sirt_eigenvalues

First Eigenvalues of a Symmetric Matrix
testlet.marginalized

Marginal Item Parameters from a Testlet (Bifactor) Model
sirt-defunct

Defunct sirt Functions
smirt

Multidimensional Noncompensatory, Compensatory and Partially Compensatory Item Response Model
sirt-utilities

Utility Functions in sirt
wle.rasch

Weighted Likelihood Estimation of Person Abilities
unidim.test.csn

Test for Unidimensionality of CSN
tetrachoric2

Tetrachoric Correlation Matrix
truescore.irt

Conversion of Trait Scores \(\theta\) into True Scores \(\tau ( \theta )\)
wle.rasch.jackknife

Standard Error Estimation of WLE by Jackknifing
xxirt_createParTable

Create Item Response Functions and Item Parameter Table
xxirt

User Defined Item Response Model
xxirt_createThetaDistribution

Creates a User Defined Theta Distribution