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irtoys

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 (44)

Binary (true/false) responses to a test

Example item parameters

Original, unscored multiple-choice responses to a test

Estimate ability

api

The api appropriateness index

Example item parameters 1PL (Bilog)

Example item parameters 2PL (Bilog)

Example item parameters 3PL (Bilog)

dpv

Draw plausible values

eap

EAP estimation of ability

erf

Plot empirical response function

est

Estimate item parameters

iif

Item information function

interactionModel

Interaction model

irf

Item response function

Item fit plot

irtoys-package

Estimate and plot IRT models for binary responses

itf

Test item fit

Maximum likelihood and Bayes Modal estimation of ability

Normal quadrature points and weights

npp

Non-parametric characteristic curves

A plot method for item information functions

A plot method for the interaction model

A plot method for item response functions

A plot method for test information functions

A plot method for test response functions

qrs

Quantiles of the ranked sum scores

read.ip.bilog

Read in parameter estimates

read.ip.icl

Read in parameter estimates

read.qu.icl

Read in quadrature

Read responses from a file

rim

Item-total regressions for the Rasch vs. the interaction model

sca

Linear transformation of the IRT scale

sco

Score a multiple choice test

scoreMetric

Sum score metric

scp

Plot observed and predicted scores against ability

sim

Simulate response data

tet

Approximate tetchoric correlation matrix

tgf

Non-parametric option curves

tia

Elementary test-item analysis

tif

Test information function

trf

Test response function

tsc

True scores with standard errors

wle

Bias-corrected (Warm's) estimates of ability

irtoys

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

v0.2.1

GPL (>= 2)

Authors

Ivailo Partchev [aut, cre], Gunter Maris [aut], Tamaki Hattori [ctb]

Initial release

2017-12-15

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