------------------- sirt NEWS ------------------------

++++++++++++++++++++++++++++++++++++++++++++++

sirt: Supplementary Item Response Theory

Alexander Robitzsch
Federal Institute for Educational Research, Innovation and 
Development of the Austrian School System (BIFIE)
Salzburg (Austria)
http://www.bifie.at

++++++++++++++++++++++++++++++++++++++++++++++

Questions or suggestions about sirt can be send to

a.robitzsch/-\bifie.at

See also URL: 
https://sites.google.com/site/alexanderrobitzsch/software


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CHANGELOG sirt
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---
Version 0.31 -- 2013-05-27
---
x speeded rasch.pml2 a bit
x fixed a bug in smirt function (thanks to Izanloo Balal)
x included function tetrachoric2 for a quick calculation
   of the tetrachoric correlation matrix
x included pbivnorm2 for the bivariate normal integral
x included rasch.pml3, a bit faster version than rasch.pml2
x eliminated warning statements in smirt and fixed a bug in 
  estimation of a and b parameters in smirt (thanks to Izanloo Balal)

---
Version 0.30  -- 2013-04-30
---
x included a C file for faster calculations in rm.hrm
  (now there is a dependency of Rcpp and RcppArmadillo)
x included smirt function for estimating the multdimensional
   noncompensatory and compensatory models
x included variational approximation for the Rasch model
x included the (Rasch) grade of membership model

---
Version 0.29  -- 2013-04-08
---
x efficient computation of eigenvalues and inverses of
  many matrices
x included facets models with item/rater intercepts and
  slopes
x initial version of the hierarchical rater model based on
  signal detection theory (DeCarlo et al., 2011)
x included function for simulating and estimating the
  Dirichlet distribution
x included grade of membership model with joint maximum 
  likelihood estimation -> gom.jml

---
Version 0.28  -- 2013-03-24
---
x included standard errors in rasch.mml2
x included marginal true score reliability for binary item 
  response data (Dimitrov, 2003; thanks to Ulrich Schroeders)

---
Version 0.27  -- 2013-02-26
---
x included classification accuracy in the Rasch model
x implemented multidimensional latent class Rasch model
   (Bartolucci, 2007)
x cleaning of help files, included several datasets and
  examples
x included log-linear smoothing of the theta distribution
   in rasch.mirtlc
x included 2PL estimation in rasch.mirtlc
x included global fit statistics in modelfit.sirt
x included log-linear smoothing of the ability distribution
   in rasch.mml2
x accelerated rasch.pml function and renamed it into rasch.pml2
x allowed for linear constraints for residual correlations
   in rasch.pml2
x accelerated latent.regression.em.raschtype and 
  plausible value routines

---
Version 0.26  -- 2013-01-17
---
x restructured rasch.mml2 function into a bit more compact code
x do not export rasch.mml and rasch.copula anymore via namespace
x included nonparametric IRT function estimation in rasch.mml2
  -> argument irtmodel='npirt' (Rossi, Wang & Ramsay, 2002)
x included multidimensional models in rasch.mml2
x added corrected AIC (AICc) in rasch.mml2 and rasch.copula2
x corrected mean and SD estimation in rasch.mml2
x fixed a bug in the calculation of the number of estimated parameters
   in rasch.copula2
x corrected rasch.mml2 function in case of fixed weights of
  trait distribution
x corrected a bug in wle.rasch
x included probabilistic Guttman model
x analytical bias correction method for JML estimation of the Rasch model
x accelerated PMML estimation algorithm
x 2PL estimation in rasch.pml

---
Version 0.25  -- 2012-10-16
---
x fixed bad numerical behavior in rasch.copula2 for Cook-Johnson
  and Frank copula models
x improved speed in yen.q3 and extended output
x speed improvement in rasch.mml and rasch.copula2
x included version rasch.mml2 with substantial speed improvements
x speed improvements for rasch.jml function

---
Version 0.24 -- 2012-09-20
---
x changed algorithms behavior of rasch.copula2 
  (parameter increments depend on number of iterations)
x corrected deviance calculation in rasch.copula

---
Version 0.23  -- 2012-08-31
---
x removed functions for running ConQuest from this package
x included Cook-Johnson and Frank copula in rasch.copula2 function
x included examples for wle.rasch.jackknife
x removed a minor printing bug in rasch.copula
x fixed a bug in jackknife.rasch.jml
x included item parameter constraints in jackknife.rasch.jml
x corrected handling of extreme responses in rasch.prox

---
Version 0.22 -- 2012-07-17
---
x included estimation of residual error correlations in rasch.pml
x restructured rasch.testlet.glmer function
x included data set reading data.read
x set a different default in rasch.mml (estimation of trait SD seemed incorrect)
x rasch.testlet.glmer: output EAPs and EAP reliability
x included loglog and cloglog link functions in rasch.testlet.glmer
x included jackknife estimation of the joint maximum likelihood
  Rasch model
x included a speeded version of rasch.copula and labelled it 
  as rasch.copula2 -> The old version rasch.copula remains in the
  package.
x output posterior distribition, EAP estimates and
  EAP reliability in rasch.copula    
x introduced probit and logit version of rasch.pml: pairwise marginal 
  likelihood estimation
x removed slight bugs (or inefficiencies) in numerical differentiation 
  in rasch.mml and rasch.copula
x renamed sim.rasch.copula into sim.rasch.dep
x included function rasch.pairwise.itemcluster for the conditional 
  pairwise estimation method for locally dependent items   
x package structure of sirtr is created
x included simulation function for Rasch copula model 
   (sim.rasch.copula)



