DFIT-package |
Differential Functioning of Items and Tests framework |
Ase1pl |
Calculates the asymptotic variance for difficulty parameter estimates under the 1pl model |
Ase2pl |
Calculates the asymptotic covariance matrix of item parameter estimates under the 2pl model |
Ase3pl |
Calculates the asymptotic covariance matrix of item parameter estimates under the 3pl model |
AseIrt |
Calculates the asymptotic covariance matrices for item parameters according with the IRT model. |
Bound3PlIpr |
Takes item parameters frp, Ipr and forces guessing to lie between 0 and 1 |
Calculate1plProb |
Calculates the item success probability under the 1PL model. |
Calculate2plProb |
Calculates the item success probability under the 2PL model. |
Calculate3plProb |
Calculates the item success probability under the 3PL model. |
CalculateGrmExp |
Calculates the expected item score under the GRM model. |
CalculateItemDifferences |
Calculates the differences between two item option characteristic curves for all options (minus one). |
CalculatePcmExp |
Calculates the expected item score under the (G)PCM model. |
Cdif |
Calculates CDIF index for an item with given item parameters of focal and reference groups. |
CrossedProbabilities |
Calculates the crossed probabilities associated with the numerator and denominator of the odds-ratio under dichotomous IRT models |
CutoffIpr |
Cut-off points for Ipr generated estimates |
DeltaMhIrt |
Obtains the ETS Delta measure for Mantel-Haneszel DIF statistic effect size. |
DFIT |
Differential Functioning of Items and Tests framework |
dichotomousItemParameters |
Sets of focal and reference item parameters from Wright (2011). |
Dtf |
Calculates DTF index for a set of items with given item parameters of focal and reference groups. |
Ipr |
Item parameter replication |
IprMh |
Mantel Haenszel for Item parameter replication |
IprNcdif |
NCDIF for Item parameter replication |
IprSam |
Signed Area Measure for Item parameter replication |
IprUam |
Unsigned Area Measure for Item parameter replication |
IrtMh |
Calculates the Mantel-Haenszel theoretical parameter when a dichotomous IRT model holds |
Ncdif |
Calculates NCDIF index for an item with given item parameters of focal and reference groups. |
PlotNcdif |
Plot the item characteristic (expected score) curve for focal and reference groups for the iiItem along with a representation of the focal group density. |
polytomousItemParameters |
Sets of focal and reference item parameters from Raju et al. (2009) |
ProductProbabilities |
Calculates the product of item response probabilities for dichotomous IRT models |
SignedArea |
Calculates Raju's Signed Area Measure index for an item with given item parameters of focal and reference groups. |
UnsignedArea |
Calculates Raju's Unsigned Area Measure index for an item with given item parameters of focal and reference groups. |