Some functions to help in the generation of binary data or to interpret m4pl models results.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: propCorrect, rmultinomial
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0 images
responses4pl
(Package: irtProb) :
Simulation of Response Patterns and Computation of the Probability of the Patterns
Simulation of response patterns and computation of the probability of the patterns according to the one, two, three and four parameters logistic item response models.~
● Data Source:
CranContrib
● Keywords: distribution
● Alias: ggr4pl, gr4pl, pggr4pl
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0 images
m4pl
(Package: irtProb) :
Multidimensional One, Two, Three and Four Person Parameters Logistic Distributions
Density, distribution function, quantile function and random generation for the multidimensional one, two, three and four person parameters logistic distributions.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: dm4pl, pm4pl, qm4pl, rm4pl
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0 images
A set of functions to manipulate modelShow class objects. is.modelShow is used to verify if the object correspond to a modelShow class object. Round.modelShowis used to control the number of decimals of the report. Finally, summary.modelShow produces different summary reports according th the report value.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: Round, Round.modelShow, is.modelShow, summary.modelShow
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0 images
responsesm4pl
(Package: irtProb) :
Simulation of Response Patterns and Computation of the Probability of the Patterns from m4pl
Simulation of response patterns and computation of the probability of the patterns according to the multidimensional one, two, three and four person parameters logistic item response models (Raiche et al., 2013).
● Data Source:
CranContrib
● Keywords: distribution
● Alias: ggrm4pl, grm4pl, pggrm4pl
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0 images
4pl
(Package: irtProb) :
One, Two, Three and Four Parameters Logistic Distributions
Density, distribution function, quantile function and random generation for the one, two, three and four parameters logistic distributions.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: d4pl, p4pl, q4pl, r4pl
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0 images
irtProb-package
(Package: irtProb) :
Utilities and Probability Distributions Related to Multidimensional Person Item Response Models (IRT)
The irtProb package was mainly developped to compute probability distributions in the context of Item Response Theory (IRT). Actually two families of models are taken into account. The first is the family of 1, 2, 3 and 4 parameters logistic fonctions. The second is a new logistic family adding 1, 2, 3 and 4 person parameters (Raiche et al., 2013). With irtProb some utilitarian functions are also available. So it is possible to generate response patterns with each family of item response models and other functions are also available to do conversion of item parameters between classical test theory and item response theory (2PL). Maximum likelihood and Maximum a posteriori estimation function of the multidimensional person paramaters are available.
checkAdequation
(Package: irtProb) :
Function to Check the Adequation of the Second Derivatives
Check the adequation of the second derivatives (hessian) for computation of variance and covariance. Use inside the function m4plEstimateMore to assure that computations can be applied to this second derivative. Problems encountered can be of not positive definitetess, singular matrix, diagonal not complitely positive. In these cases inversion of the matrix is not posssible or variances cannot be computed from the inverse of the diagonal.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: checkAdequation
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0 images
conversion
(Package: irtProb) :
Functions to Convert from and to CTT and IRT Models
ctt2irt and irt2ctt are converter functions to change the parametrization of item parameters from and to classical test theory (difficulty and discrimination parameters) and item response theory (difficulty and discrimination parameters). Consequently, the conversion is only valid between ctt and 2 parameters logistic or normal models.
● Data Source:
CranContrib
● Keywords: distribution
● Alias: ctt2irt, irt2ctt
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0 images
providing 
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