irtoys v0.2.1


Monthly downloads



A Collection of Functions Related to Item Response Theory (IRT)

A collection of functions useful in learning and practicing IRT, which can be combined into larger programs. Provides basic CTT analysis, a simple common interface to the estimation of item parameters in IRT models for binary responses with three different programs (ICL, BILOG-MG, and ltm), ability estimation (MLE, BME, EAP, WLE, plausible values), item and person fit statistics, scaling methods (MM, MS, Stocking-Lord, and the complete Hebaera method), and a rich array of parametric and non-parametric (kernel) plots. Estimates and plots Haberman's interaction model when all items are dichotomously scored.

Functions in irtoys

Name Description
ability Estimate ability
b2 Example item parameters 2PL (Bilog)
b3 Example item parameters 3PL (Bilog)
dpv Draw plausible values
Unscored Original, unscored multiple-choice responses to a test
Scored Binary (true/false) responses to a test
b1 Example item parameters 1PL (Bilog)
Scored2pl Example item parameters
iif Item information function
api The api appropriateness index
mlebme Maximum likelihood and Bayes Modal estimation of ability
itf Test item fit
normal.qu Normal quadrature points and weights
irf Item response function
irfPlot Item fit plot
est Estimate item parameters
interactionModel Interaction model
erf Plot empirical response function
irtoys-package Estimate and plot IRT models for binary responses
read.ip.icl Read in parameter estimates
plot.trf A plot method for test response functions
plot.tif A plot method for test information functions
plot.iif A plot method for item information functions
npp Non-parametric characteristic curves
tgf Non-parametric option curves
plot.imp A plot method for the interaction model
tia Elementary test-item analysis
plot.irf A plot method for item response functions
sim Simulate response data
read.qu.icl Read in quadrature
tet Approximate tetchoric correlation matrix
scoreMetric Sum score metric
read.resp Read responses from a file
scp Plot observed and predicted scores against ability
rim Item-total regressions for the Rasch vs. the interaction model
tsc True scores with standard errors
wle Bias-corrected (Warm's) estimates of ability
qrs Quantiles of the ranked sum scores
read.ip.bilog Read in parameter estimates
sca Linear transformation of the IRT scale
sco Score a multiple choice test
tif Test information function
trf Test response function
eap EAP estimation of ability
No Results!

Vignettes of irtoys

No Results!

Last month downloads


Type Package
Date 2017-12-15
LazyLoad yes
LazyData yes
License GPL (>= 2)
Collate 'ability.R' 'estimate.R' 'itemfit.R' 'nonpar.R' 'readin.R' 'scale.R' 'tracelines.R' 'utils.R' 'irtoys-package.R' 'interaction.R'
VignetteBuilder knitr
RoxygenNote 6.0.1
NeedsCompilation yes
Packaged 2017-12-15 12:47:57 UTC; ivailo
Repository CRAN
Date/Publication 2017-12-15 13:33:18 UTC
suggests knitr , MASS
depends ltm , sm
Contributors Gunter Maris, Tamaki Hattori

Include our badge in your README