Learn R Programming

⚠️There's a newer version (1.1) of this package.Take me there.

DFIT (version 1.0-3)

Differential Functioning of Items and Tests

Description

A set of functions to perform Raju, van der Linden and Fleer's (1995, doi:10.1177/014662169501900405) Differential Functioning of Items and Tests (DFIT) analyses. It includes functions to use the Monte Carlo Item Parameter Replication approach (Oshima, Raju, & Nanda, 2006, doi:10.1111/j. 1745-3984.2006.00001.x) for obtaining the associated statistical significance tests cut-off points. They may also be used for a priori and post-hoc power calculations (Cervantes, 2017, doi:10.18637/jss.v076.i05).

Copy Link

Version

Install

install.packages('DFIT')

Monthly Downloads

277

Version

1.0-3

License

GPL (>= 2)

Maintainer

Victor H Cervantes

Last Published

January 6th, 2017

Functions in DFIT (1.0-3)

CalculateItemDifferences

Calculates the differences between two item option characteristic curves for all options (minus one).

Calculates the asymptotic variance for difficulty parameter estimates under the 1pl model

Calculates the asymptotic covariance matrix of item parameter estimates under the 2pl model

Calculate1plProb

Calculates the item success probability under the 1PL model.

Calculates the asymptotic covariance matrix of item parameter estimates under the 3pl model

Calculates the asymptotic covariance matrices for item parameters according with the IRT model.

Calculate2plProb

Calculates the item success probability under the 2PL model.

CalculateGrmExp

Calculates the expected item score under the GRM model.

Takes item parameters frp, Ipr and forces guessing to lie between 0 and 1

Calculate3plProb

Calculates the item success probability under the 3PL model.

CrossedProbabilities

Calculates the crossed probabilities associated with the numerator and denominator of the odds-ratio under dichotomous IRT models

Item parameter replication

Obtains the ETS Delta measure for Mantel-Haneszel DIF statistic effect size.

Cut-off points for Ipr generated estimates

Calculates CDIF index for an item with given item parameters of focal and reference groups.

Differential Functioning of Items and Tests framework

CalculatePcmExp

Calculates the expected item score under the (G)PCM model.

Mantel Haenszel for Item parameter replication

Calculates DTF index for a set of items with given item parameters of focal and reference groups.

dichotomousItemParameters

Sets of focal and reference item parameters from Wright (2011).

Calculates Raju's Signed Area Measure index for an item with given item parameters of focal and reference groups.

Calculates Raju's Unsigned Area Measure index for an item with given item parameters of focal and reference groups.

Calculates the Mantel-Haenszel theoretical parameter when a dichotomous IRT model holds

Unsigned Area Measure for Item parameter replication

Plot the item characteristic (expected score) curve for focal and reference groups for the iiItem along with a representation of the focal group density.

Signed Area Measure for Item parameter replication

Calculates NCDIF index for an item with given item parameters of focal and reference groups.

ProductProbabilities

Calculates the product of item response probabilities for dichotomous IRT models

NCDIF for Item parameter replication

polytomousItemParameters

Sets of focal and reference item parameters from Raju et al. (2009)