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Implementation of a class of hierarchical item response theory (IRT) models where both the mean and the variance of latent preferences (ability parameters) may depend on observed covariates. The current implementation includes both the twoparameter latent trait model for binary data and the graded response model for ordinal data. Both are fitted via the ExpectationMaximization (EM) algorithm. Asymptotic standard errors are derived from the observed information matrix.
Package details 


Author  Xiang Zhou [aut, cre] 
Maintainer  Xiang Zhou <xiang_zhou@fas.harvard.edu> 
License  GPL (>= 3) 
Version  0.3.0 
URL  http://github.com/xiangzhou09/hIRT 
Package repository  View on CRAN 
Installation 
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