********************************************************
****       CHANGES IN TAM PACKAGE VERSIONS          ****
********************************************************


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

Test Analysis Modules (TAM)
T. Kiefer, A. Robitzsch, & M. Wu

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mailto:
-------
Alexander Robitzsch
robitzsch@ipn.uni-kiel.de

For reporting a bug, please always provide a reproducible R script 
and (if necessary) a corresponding dataset.

URL:
----

For TAM tutorials see
http://www.edmeasurementsurveys.com/TAM/Tutorials/


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



-------------------------------------------------------------
VERSIONS TAM 2.0  |  2017-04-12  |  Last: TAM 2.0-37
-------------------------------------------------------------

FEATURES:
* extended multiple group models to multidimensional IRT
  models in 'tam.mml.3pl' (see Example 1.9)
 
BUG FIXES:
* fixed a bug in 'tam.mml.3pl' with option skillspace='normal'
  and estimated means (i.e., means not fixed to zero)
* fixed a bug in handling multiple groups in 'tam.mml.3pl'
  (thanks to Laura Zieger)

NOTES:
* changed calculation of item response probabilities to avoid
  numerical overflow
* removed dependencies to the packages msm and tensor
* included example for extracting posterior probabilities in
  Rasch mixture models (requested by Ling Liaw)
* changed order of items in output of value 'item' in 'tam.mml.mfr'  
* exported utility functions 'tam_packageinfo', 'tam_print_call' and
  'tam_rsessinfo' for usage in other packages
* added 'logLik' method for objects of class 'tam.jml'
* moved function 'tam.jml2' into 'tam.jml' (now available as the 
  default with argument 'version=2')

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* data.geiser (2), tam.mml.3pl (1.9), tam.jml (1,2,3)

-------------------------------------------------------------
VERSIONS TAM 1.99999  |  2017-03-02  |  Last: TAM 1.99999-31
-------------------------------------------------------------

FEATURES:
* ---
 
BUG FIXES:
* removed adjustment for WLE estimation of extreme scores in 
  'adj' in 'tam.wle'. Now, WLE estimation in TAM should be
  equivalent to ConQuest software, sirt::IRT.mle and
  mirt::fscores. The adjustment 'adj' is only applicable for
  MLE estimation in 'tam.wle'. The WLE estimation of the recent
  TAM version is equivalent to 'adj=0' of previous TAM versions.

NOTES:
* restructured Rcpp functions

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.99993 (2017-02-06)  --  CRAN 1.99993-0
-------------------------------------------------------------

FEATURES:
* ---
 
BUG FIXES:
* changed handling of item names in 'tam.mml.mfr' back to
  TAM 1.995-0 version (problem communicated by Barth Riley)
* fixed a bug in 'tam.mml.2pl' for irtmodel='GPCM.design' with
  provided design matrices for item slopes
  (thanks to Matthias Trendtel) 

NOTES:
* ---

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.99992 (2017-01-23)  --  CRAN 1.99992-0
-------------------------------------------------------------

FEATURES:
* ---
 
BUG FIXES:
* fixed incorrect handling of item renaming in 'tam.mml.mfr'
  (thanks to Barth Riley) 
* fixed a bug in calculation of p values in 'tam.fit'
  (thanks to David Torres Irribarra)
* fixed a bug in 'IRT.simulate' with used argument 'nobs'
  (thanks to Mark Dulhunty)
* the fixing of the random seed within the 'tam.fit' function
  is removed (thanks to Sebastian Weirich)
* fixed crucial bug in 3PL estimation in 'tam.mml.3pl' function
  (thanks to Petra Kleiber)

NOTES:
* stop estimation in 'tam.jml' (and 'tam.jml2') if there are persons
  with only missing item responses (communicated by Ricardo Primi)
* included standard errors for constrained parameters in 'tam.mml.mfr'
  similar to the software ConQuest software 
  (requested by Florian Keller und Domenico Angelone)

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.995    (2016-05-31)  --  CRAN 1.995-0
-------------------------------------------------------------

FEATURES:
* ---

BUG FIXES:
* fixed a bug in 'tam.fit' when proving a fit matrix F with
  missing labels (thanks to Maxim Morin)

NOTES:
* included argument 'version' in 'msq.itemfit'. Another Rcpp
  implementation (version=2) of the fit calculation has been 
  added which avoids the storage of memory intensive objects
  (previous function; version=1). Additionally, a pure 
  R function of calculating fit can be requested using 
  version=3 (thanks to Frank Musekamp).

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.99    (2016-04-15)  --  CRAN 1.99-6
-------------------------------------------------------------

FEATURES:
* ---

BUG FIXES:
* fixed a bug in 'tam.wle' which occured if some persons were
  eliminated from the analysis
* fixed a recently induced bug in 'tam.wle' estimation of
  multidimensional models (thanks to Sascha Bernholt)

NOTES:
* ---

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.17   (2016-03-11)  --  CRAN 1.17-0
-------------------------------------------------------------

FEATURES:
* included function 'IRTLikelihood.ctt' which computes the 
  individual likelihood under classical test theory and
  normally distributed measurement errors

BUG FIXES:
* fixed a bug in plausible value imputation 'tam.pv' in case 
  of 'normal.approx=FALSE' (thanks to Matthias Trendtel)
* fixed a bug in plotting 'png' files in 'plot.tam'
  (thanks to Rainer Alexandrowicz) 
* fixed a bug in calculating standard errors with only one
  estimated xsi parameter
* fixed a crash in 'tam.jml2'
* fixed a bug in 'tam.wle' when using the argument 'score.resp'

NOTES:
* included Example 24 for specifying sum constraints in partial
  credit models (requested by Chen-Wei Liu) 
* output of 'tam.wle' is now an object of class 'tam.wle'.
  A print method for this class is defined.
* WLE reliability in 'tam.wle' is now calculated by taken
  sample weights 'pweights' into account
* included Example 11 of 'tam.mml.3pl' with mixed item 
  response format (thanks to a correspondence with Andreas Seifert)
* included utility functions for weighted statistics 'weighted_Stats'
* included utility functions 'WLErel' and 'EAPrel' for computation of 
  WLE/EAP reliability
* added 'print' methods for tam classes ('tam.mml', 'tamaan', ...)
* added S3 methods 'Scale' and 'DescribeBy'. The application of these
  methods to object classes will be included in future TAM versions.
* slight change in summary output of 'IRT.modelfit'

DATASETS INCLUDED OR MODIFIED:
* ---

EXAMPLES INCLUDED OR MODIFIED:
* tam.mml (24), WLErel (1), tam.mml.3pl (11), weighted_Stats (1,2,3),
  IRTLikelihood.ctt (1), tam.pv (2)

-------------------------------------------------------------
CHANGES IN VERSION 1.16   (2016-01-31)  --  CRAN 1.16-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a crucial bug in estimation of 'tam.mml.2pl', 
  irtmodel='GPCM.design'

Notes:
* included a warning message in 'IRT.truescore' when
  not all values in the theta grid can be computed
* cleaned namespace file and defined imported functions
  in a more explicit way
* included argument 'Q' in 'IRT.truescore' function which
  allows for computation of weighted true scores
  (thanks to David Sichau)
* fixed a bug in 'tam.mml.2pl' with irtmodel='GPCM.design'
  in case of blank categories

Datasets included or modified:
* ---

Examples included or modified:
* IRT.truescore (2)

-------------------------------------------------------------
CHANGES IN VERSION 1.15   (2015-12-15)  --  CRAN 1.15-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a bug in postprocessing of parameter names in 'tam.mml.mfr'
  with the option "constraint='items'"
* avoided NA entries in posterior calculation in 'tam.mml' and
  'tam.mml.2pl' 

Notes:
* corrected output of likelihood when minimum value was not
  obtained in last iteration
* changed behavior of parameters 'max.increment' and 'increment.factor'
  in 'tam.mml.mfr' which should result in more stable deviance
  behavior
* included attributes 'pid' and 'pweights' in 'IRT.likelihood' and
  'IRT.posterior'
* included optional argument 'gamma.init' for 'tam.mml.2pl' and 
  irtmodel='GPCM.design'
* included argument 'item.elim' in 'tam.mml', 'tam.mml.2pl' and 
  'tam.mml.3pl' which prevents the omission of items with a 
  maximum score of zero (suggested by Anja Mikolajetz)
* changed output of 'pweights' to original provided person weights,
  not the transformed person weights

Datasets included or modified:
* ---

Examples included or modified:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.14   (2015-10-15)  --  CRAN 1.14-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a bug in creating design matrices with more than 9 levels
  of a factor in a facet for facet models with items with
  varying number of categories
* fixed a recently introduced bug in 'tam.pv' which occured due
  to a change in the list of arguments in auxiliary function 
  'stud_prior.v2' (thanks to Florian Gigl)

Notes:
* ---

Datasets included or modified:
* ---

Examples included or modified:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.13   (2015-08-29)  --  CRAN 1.13-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a recently introduced bug in TAM 1.12-0 when
  creating the item parameter table

Notes:
* extended value 'item' to output of category 0 if design
  matrices put values on zero categories

Datasets included or modified:
* ---

Examples included or modified:
* tam.mml (23)



-------------------------------------------------------------
CHANGES IN VERSION 1.12   (2015-08-27)  --  CRAN 1.12-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a recently included bug (in TAM 1.11-0) in 
  'tam.mml.3pl' estimation when guessing parameters are
  estimated (thanks to Rolf Strietholt and Laura Zieger)

Notes:
* ---

Datasets included or modified:
* ---

Examples included or modified:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.11   (2015-08-11)  --  CRAN 1.11-0
-------------------------------------------------------------

Features:
* ---

Bug fixes:
* fixed a recently included bug in TAM 1.10-0 in calculation 
  of deviance in 'tam.mml.2pl', 'tam.mml.3pl' and 'tam.mml.3pl'
  (thanks to Christopher Gess)
* fixed a recently included bug in TAM 1.9-0 in estimation
  of models with estimated means of latent trait
  (thanks to Frank Musekamp)

Notes:
* included guessing parameters and its standard errors in
  output of 'tam.mml.3pl' ('guess' and 'se.guess')

Datasets included or modified:
* ---

Examples included or modified:
* ---

-------------------------------------------------------------
CHANGES IN VERSION 1.10   (2015-07-25)  --  CRAN 1.10-0
-------------------------------------------------------------

Features:
* added simulation function 'IRT.simulate'
* added function 'IRT.truescore' which converts theta 
  scores into true scores

Bug fixes:
* fixed a bug in calculation of expected counts 

Notes:
* included argument 'dev_crit' in 'control' in tam 
  functions which allows a decision whether change in 
  absolute deviance difference (dev_crit="absolute") 
  or in relative deviance differences (dev_crit="relative")
  should be assessed.
* extended 'IRT.itemfit' S3 method to objects of classes
  generated in TAM (suggested by Karoline Sachse)
* included item-wise calculation of thresholds according
  to Ali, Chang and Anderson (2015) suggestion in 
  'IRT.threshold'

Datasets included or modified:
* ---

Examples included or modified:
* IRT.itemfit.tam (1,2), IRT.threshold (3), 
  IRT.simulate (1,2,3,4), IRT.truescore (1)

-------------------------------------------------------------
CHANGES IN VERSION 1.9   (2015-06-30)  --  CRAN 1.9-0
-------------------------------------------------------------

Features:
* included accelerators of the EM algorithm according to
  Ramsay (1975) and Yu (2012). In the recent TAM package
  version, no acceleration is used as an default.

Bug fixes:
* Fixed recently broken 'tam.mml.3pl' function when the
  design matrix E is used.

Notes:
* small speedup for large samples of students in
  unidimensional models

Datasets included or modified:
* ---

Examples included or modified:
* tam.mml (21,22)

-------------------------------------------------------------
CHANGES IN VERSION 1.8   (2015-06-26)  --  CRAN 1.8-0
-------------------------------------------------------------

Features:
* added S3 method 'IRT.informationCurves' for computing
  item and test information curves (suggested by Ray Opao) 

Bug fixes:
* fixed a crucial bug in 'tam.mml.3pl' for mixed dichotomous 
  and polytomous data occur and guessing parameters
  are estimated (thanks to Matthias Trendtel)

Notes:
* added the argument 'Q.fixed' in 'tam.mml.3pl' for usage
  of fixed item loadings
* small speedup in M-step for datasets with large number of items

Datasets included or modified:
* ---

Examples included or modified:
* tam.mml (15c), tam.mml.3pl (10), IRT.informationCurves (1,2)


-------------------------------------------------------------
CHANGES IN VERSION 1.7   (2015-06-05)  --  CRAN 1.7-1
-------------------------------------------------------------

Features:
* included S3 method 'IRT.residuals' (and 'residuals') 
  for objects of classes 'tam.mml', 'tam.mml.2pl' and 
  'tam.mml.mfr'
* added function 'msq.itemfitWLE' (see ?msq.itemfit) 
  which computes outfit and infit statistics based on 
  weighted likelihood estimates (WLEs)
* added function 'tam.Q3' for calculation of Q3 statistics
  based on WLEs

Bug fixes:
* fixed a bug in 'tam.mml.3pl' (which led to an error)
  in case of multiple groups
* fixed a bug in 'tam.mml.mfr' when no person identifiers
  were provided (thanks to by Michal Modzelewski)  
* fixed a bug in 'msq.itemfit' with differing number of 
  categories per item
* fixed a bug in calculation of expected counts for 
  multifaceted models
* fixed a bug in 'tam.mml.mfr' with non-unique combinations
  of person and facet identifiers

Notes:
* speeded 'tam.mml.3pl' for models with many item parameters
* added argument 'change' in 'plotDevianceTAM' for plotting
  iteration progress in deviance values
* added arguments 'progress' and 'output.prob' in 'tam.wle'
* added summary of fit statistics in output of 'msq.itemfit' and
  'summary.msq.itemfit'
* included sample size of each item pair in 'tam.modelfit' output
  value 'stat.itempair'
* renamed datset 'sim.rasch' into 'data.sim.rasch'. The same 
  procedure was conducted for all other 'sim.xxx' datasets.

Datasets included or modified:
* ---

Examples included or modified:
* IRT.residuals (1), msq.itemfit (1,2,3), tam.modelfit (4)

-------------------------------------------------------------
CHANGES IN VERSION 1.6   (2015-04-03)  --  CRAN 1.6-0
-------------------------------------------------------------

Features:
* included function 'IRT.drawPV' for drawing plausible values
  based on individual posterior (output of 'IRT.posterior')

Bug fixes:
* fixed a bug for input of a B loading matrix with no item labels
* fixed a bug in 'plot.tam' with missing data in item responses
  (bug fix provided by Michal Modzelewski)
* corrected an included bug in recent TAM versions in AIC
  calculation (thanks to Simon Grund)
* fixed a bug in variance fixing in 'tam.fa' which occured in a 
  recent TAM version due to changes in defaults in 'tam.mml.2pl'
* fixed a bug when constraining of item parameters was ignored
  in 'tamaan' (thanks to Stefan Behrendt)

Notes:
* speeded data/design matrix preparation phase in 'tam.mml.mfr'
* included internal function 'tamcat' for analyzing computation time
* changed numerical behavior in 'tam.mml.mfr' in order to avoid a zero sum 
  of all individual posterior probabilities (thanks to Roman Freunberger)
* included argument 'xsi.setnull' in 'tam.mml.mfr' for convenient
  fixing of xsi parameter groups. A warning is now given if the
  combination of person and facet identifiers is not unique.     
* allowed also explicit use of facets without effects in 'tam.mml.mfr'
  on 'formulaA', e.g. 'item*step + 0*rater' sets all rater effects
  to zero
* included warning in 'tam.wle' if the WLE is (possibly) not estimable
  (suggested by Rainer Alexandrowicz)

Datasets included or modified:
* ---

Examples included or modified:
* tam.mml (19, 20, 10a), IRT.drawPV (1), tamaan (1.9)

-------------------------------------------------------------
CHANGES IN VERSION 1.5   (2015-02-24)  --  CRAN 1.5-2
-------------------------------------------------------------

Features:
* included S3 methods 'IRT.expectedCounts', 'IRT.modelfit',
  'predict' and 'IRT.data' for fitted models in TAM
* included item fit statistic on item level 'msq.itemfit' 
  as an alternative to the simulation based 'tam.fit' function 
* included linear approximation for confirmatory factor analysis  
  'IRT.linearCFA'

Bug fixes:
* fixed a bug in plausible value imputation in multidimensional
  models and normal approximation (reported by Dan Su)
* changed resp in output of 'tam.mml', 'tam.mml.2pl' and
  'tam.mml.3pl' to output the original used data with missings
  (thanks to Matthias Trendtel)
* extended tam.modelfit to handle multi matrix design appropriately
* changed defaults in 'est.variance' if 'variance.fixed' is provided
  in 'tam.mml.2pl'. The previous default led to bugs in the
  tamaan function. (reported by Christoph Duchhardt)

Notes:
* added output values 'xsi.fixed.estimated', 'B.fixed.estimated'
  for default item parameter fixings in tam.mml, tam.mml.2pl, 
  tam.mml.mfr and tam.mml.3pl (suggested by Matthias Trendtel)
* extended tan.modelfit function for more flexible input to
  allow for assessing model fit for objects which were not
  fitted in TAM ('tam.modelfit.IRT', 'tam.modelfit.args')
* added 'IRT.likelihood' and 'IRT.posterior' S3 method for 
  object of class 'tam.latreg'
* extended 'plotctt' and 'plot.tam' the using graphics package
  in addition to lattice (suggested by Michal Modzelewski)
* included function for computing Thurstonian thresholds ('IRT.threshold')   

Datasets included or modified:
* ---

Examples included or modified:
* tam.mml (1,5t,6), IRT.expectedCounts.tam (1), tam.modelfit (1),
  predict (1), msq.itemfit (1), IRT.linearCFA (1,2),
  IRT.threshold (1,2)

-------------------------------------------------------------
CHANGES IN VERSION 1.4   (2015-01-15)  --  CRAN 1.4-1
-------------------------------------------------------------

Features:
* included function 'cfa.extract.itempars' for extracting
  item parameters from a fitted confirmatory factor analysis
  with the cfa function in lavaan package
* included the function 'IRTLikelihood.cfa' for extracting 
  the individual likelihood from fitted confirmatory factor
  analyses
* included an S3 method 'IRT.WrightMap' which is a wrapper
  to the WrightMap package

Bug fixes:
* fixed a bug for item response dataset with only one column
* fixed a bug in tamaan function when applied to TYPE="TRAIT"
  and models without guessing parameters
* fixed a bug in plot.ctt function for input of item response
  data with only one columns (thanks to Michal Modzelewski)

Notes:
* added item types 'PCM(kk)' and 'GPCM(kk)' for smoothing
  item intercepts in tamaan function
* included a summary method for 'tam.fit'  
* included 'MEASERR' convenience method for single indicators
  with measurement errors in 'lavaanify.IRT'
* changed some internal handling in 'lavaanify.IRT' due to
  announced changes in lavaan 0.5-18 in 'lavaanify'
* changed equality constraints in the section "MODEL CONSTRAINT"
  in 'tamaanify' to the usage of "==" instead of "=" (as in lavaan)

Datasets included or modified:
* data.ctest2

Examples included or modified:
* cfa.extract.itempars (1), IRTLikelihood.cfa (1),
  tamaan (2), tam.fit (1,2), data.geiser (2), tam.latreg (2,3),
  IRT.WrightMap (1,2,3,4), data.cqc (1,2,3), lavaanify.IRT (6)

-------------------------------------------------------------
CHANGES IN VERSION 1.3   (2015-01-06)  --  CRAN 1.3
-------------------------------------------------------------

Features:
* included option for sum constraints on item intercepts
  (constraint="items") in 'tam.mml'.
  For polytomous data, this option automatically specifies
  irtmodel="PCM2".
* included truncated normal prior distributions for
  gammaslope parameters in 'tam.mml.3pl'
* included 'tamaan' and 'tamaanify' functions for more
  more convenient model specifications in TAM
* included 'doparse' function as a shortcut for writing
  loops in model syntax
* included item-category specific curves in 'plot.tam' using  
  the argument type="items" (suggested by Cheng-Hsuan Li and
  Michal Modzelewski)
* plot function for type="items" now also works for multidimensional
  item response models with between item dimensionality
* included normal approximation and sampling of regression 
  coefficients for plausible value imputation ('tam.pv') for 
  multidimensional item response models. 
  The theta grid can also be fixed (argument theta.model=TRUE)
  and is taken from the fitted model.
* included the function 'tampv2datalist' for converting plausible
  values and a set of covariates into a list of multiply imputed
  datasets 
* included the function 'tam.latreg' which performs a latent
  regression model in which only the individual likelihood is 
  needed as an input

Bug fixes:
* corrected algorithmic stopping criteria in 'tam.mml.3pl'
* fixed a bug in 'tam.mml.2pl' when design matrix B.fixed 
  for fixed loadings contains only one row
* another bug was fixed by Michal Modzelewski in data preparation
  in the multi-facet function 'tam.mml.mfr'
* fixed a bug in estimation routines if a dataset resp is provided
  without column names (thanks to Alec Nyce)

Notes:
* included parametrization of mean item intercept (irtmodel="PCM2")
  in output of tam.mml and tam.mml.2pl (value item$xsi.item)
* included nonlinear terms in lavaan syntax in 'lavaanify.IRT'
* included option for initial delta parameters in 'tam.mml.3pl'
* added AIC3 information criterion in summary
* included datasets data.geiser and data.janssen for latent
  class analysis and mixture Rasch analysis (thanks to
  Christian Geiser and Anne Janssen)
* included Example 3 in 'tam.wle' comparing WLE person parameter
  estimates from the  TAM and the PP package
* included Example 3 in 'tam.threshold' for creating Wright maps
  with the WrightMap package

Datasets included or modified:
* data.geiser, data.janssen, data.janssen2

Examples included or modified:
* tam.modelfit (3), tam.mml (1,4,5,6,13,18), lavaanify.IRT (3,4),
  tam.mml.3pl (1.6b,4,7,8,9), tamaanify (1,2), tamaan (1,2), 
  plot.tam (1,2), tam.wle (3), tam.threshold (3), tam.pv (2,3),
  tam.latreg (1)

-------------------------------------------------------------
CHANGES IN VERSION 1.2   (2014-11-22)  --  CRAN 1.2
-------------------------------------------------------------

Features:
* included fit of constrained facet parameters for output
  of 'tam.mml.mfr'
* included extended lavaan syntax 'lavaanify.IRT'. This
  function was previously included in sirt package as
  'lavaanify.sirt'. 
* added argument 'gammaslope.center' in 'tam.mml.3pl' for 
  centering item parameters within iterations in estimation 
* included an argument of fixing person parameters in 'tam.jml'
  (see tam.jml, Example 1)  
* added S3 methods for fitted models in TAM: 
  'logLik', 'IRT.likelihood', 'IRT.posterior', 'IRT.irfprob', 
  'IRT.factor.scores'. These S3 methods were defined in the
  recent version of the CDM (>= 4.0) package.

Bug fixes:
* improved model identification in 'tam.mml.mfr' in case
  of differing number of categories per item and fixed
  a bug in creating the A matrix (thanks to Michal Modzelewski). 
* fixed a miscount of number of estimated parameters in
  multiple group models (thanks to Michal Modzelewski). 
* fixed incorrect handling of irtmodel="PCM2" in 'tam.mml'
  for multidimensional models (thanks to Chen-Wei Liu)
* fixed a bug in 'tam.jml2' when some item parameters were
  fixed with the xsi.fixed argument
* fixed a bug in fit calculation for tam.jml objects
  (thanks to Hillary Ferral)

Notes:
* included Rcpp based version of item fit calculation to
  reduce computational time
* changed calculation of tam.fit in case of missing item responses
  which substantially changes fit statistics especially for
  faceted models.  
* changed handling of simulating abilities in 'tam.fit'
* included p values in output for fit statistics in 'tam.fit'
* included estimation of Thurstonian thresholds for multidimensional
  models 
* added an example of a 2PL mixture distribution IRT model with
  two latent classes (tam.mml.3pl, Simulated Example 8)
* changed summary layout in 'tam.mml.3pl'
* made item parameter estimation in 'tam.jml' more computationally
  efficient
* added anova method for 'tam.mml.3pl'
* added value of the individual likelihood in 'tam.mml',
  'tam.mml.2pl' and 'tam.mml.3pl'

Datasets included or modified:
* rating dataset data.exJ03 (provided by Matt Barney)

Examples included or modified:
* tam.fit (4), tam.threshold (2), tam.mml.3pl (7,8), lavaanify.IRT (1,2),
  tam.jml (1,4), IRT.likelihood.tam (1), IRT.factor.scores (1),
  IRT.irfprob (1)

-------------------------------------------------------------
CHANGES IN VERSION 1.1   (2014-10-19)  --  CRAN 1.1
-------------------------------------------------------------

Features:
* added user defined variance function in tam.mml and
  tam.mml.2pl
* added user defined constraints on slope parameters
  in 'tam.mml.3pl'

Bug fixes:
* fixed a bug in deviance computation in 'tam.mml.3pl' when
  stochastic nodes are used
* (hopefully) fixed computational problems in multidimensional models
  with nearly singular covariance matrix 
  (thanks to a discussion with Johannes Hartig)  

Notes:
* added a plot function 'plot.ctt' accompanying the classical test 
  theory based statistic
* fixed a bug in creation of design matrices in faceted models with
  differing categories per item (thanks to Michal Modzelewski). 
  Note that the treatment of faceted models is still not compatible
  with other software (like ConQuest). A substantial bug fix
  is planned in future TAM relaeses. 

Datasets included or modified:
* data.ctest1 (thanks to HGP)

Examples included or modified:
* tam.fit (4), tam.mml (17), tam.ctt (1)

-------------------------------------------------------------
CHANGES IN VERSION 1.0-3.18 (2014-09-08)  --  CRAN 1.0-3.18-1
-------------------------------------------------------------

Bug fixes:
* modified incorrectly calculated thresholds with 'tam.threshold'
  for multidimensional models (reported by Janine Buchholz and
  Joerg-Henrik Heine)

Notes:
* included SRMSR fit statistic in tam.modelfit
* included argument "Nsimul" in "tam.fit" which improves
  calculation of fit statistics

-------------------------------------------------------------
CHANGES IN VERSION 1.0-3 (2014-06-27)  --  CRAN 1.0-3
-------------------------------------------------------------

Features:
* included model fit statistics (Q3, SRMR, MADRESIDCOV): 'tam.modelfit'
* included 'tam.mml.3pl' for 3PL estimation, general design
  matrices for item slopes and options for discrete 
  latent variables (estimation of latent class models,
  located latent class model, skew distributions,
  mixed IRT models, cognitive diagnosis models, ...
  is now possible)
* extended tam.pv for objects of class 'tam.mml.3pl'
* speeded data preparation of faceted models a bit
* tam.se now computes standard errors for estimated slope parameters, B 
  (for irtmodel in c("2PL", "GPCM", "2PL.groups")); highly experimental 
  for irtmodel="GPCM.design"). 
* plot.tam now prints a message about the location of the exported graphics.
* plot.tam has a new argument 'items' for selecting the items to
  be displayed. RD-file adjusted.
* plot.tam has new arguments 'export.type="png"' and "export.args=list()" for 
  selecting the file type for the graphics export. The supported file types 
  are those supported by ?dev.new. The argument 'export.args=list()' is 
  for specifying a list of arguments for the export device method.
* tam.threshold has a new argument prob.lvl to set the probability level of 
  the thresholds.

Bug fixes:
* fixed a bug in pid output in object 'person' for multidimensional models
  (thanks to Sebastian Weirich)
* fixed a bug in variance estimation for multiple group 2PL models
* included 'designMatrices.mfr2' for a provisional bug fix
  for multifaceted models with differing number of categories
  per item (see Example 16 in tam.mml; thanks to Christoph Duchhardt)
* fixed a bug in 'tam.mml.mfr' for differing number of categories
  per item -> now a xsi vector with parameter fixings to values 
  of 99 is used 
* plot.tam is debugged regarding the case of missing WLEs for some 
  person (thanks to Florian Buchwald). 
* plot.tam now doesn't throw a warning when the 'Plots' directory 
  already exists.
* fixed a bug in plot.tam for cross-platform accordance (thanks to Uli Keller).
* fixed a bug in tam.fit with missing item scores
* fixed a bug in tam.jml so that ../Tutorials/6Population.htm now runs without 
  error.

Notes:
* tam.fit is experimental for objects obtained from tam.mml.mfr.
* changed convergence behavior in tam.wle (thanks to Peter Harych)
* changed item sorting in output object 'item'
* tam.mml(/.2pl/.mfr) methods now return Q, tam.mml.2pl additionaly returns
  B.fixed, basispar, E, and est.slopegroups objects. RD-file adjusted.
* tam.jml(/.jml2) do not return fit statistics anymore. Item and person fit can
  be obtained by a call to tam.fit (/.jml.fit).
* in case of multidimensional analyses, we recommend an update of 
  the R-package mvtnorm to version 0.9-99992 or higher.
* extended example 13 in tam.mml.Rd to the case of polytomous longitudinal 
  data (requested by and thanks to Florian Buchwald)
* extended example 6 in tam.mml.Rd to the specification of sum constraints 
  on the item parameters in a PCM model for differing number of categories.
* Some minor changes in RD-files (eg., irtmodel for argument 'E' in 
  tam.mml.2pl is "GPCM.design", theta value in tam.jml is "MLE in final step").

-------------------------------------------------------------
CHANGES IN VERSION 1.0-2 (2014-03-26)  --  CRAN 1.0-2   --  CRAN 1.0-2.1
-------------------------------------------------------------

* fixed a Bug in the optional specification of a B matrix
  in tam.mml.mfr
* new faster tam.mml.wle2; included Rcpp helper functions for 
  tam.mml.wle2 for fast computation; tam.mml.wle2 new 
  reference in tam.wle for objects of class tam.mml, rd-file
  adapted
* tam.mml.mfr now accepts polytomous data with more than 
  ten categories per item
* specification of response matrix in 'long format' fixed,
  see example section (thanks to Takuya Yanagida)
* some minor changes in usability (eg., pid can be specified as 
  vector, one-column matrix or data.frame)

-------------------------------------------------------------
CHANGES IN VERSION 1.0 (2014-02-02)  --  CRAN 1.0-0  --  CRAN 1.0-1
-------------------------------------------------------------

* updated DESCRIPTION and NAMESPACE due to changes in Rcpp
* change in package maintenance: Thomas Kiefer is now
  the package maintainer
* fixed a bug in item labeling in tam.se
  (thanks to Sebastian Weirich)
* fixed a bug in labeling of reduced reponse matrices in 
  tam.mml.mfr
* fixed some examples in .Rd files

-------------------------------------------------------------
CHANGES IN VERSION 0.91/0.99 (2013-11-02)  --  CRAN 0.99-7
-------------------------------------------------------------

* added 'AXsi_' as value in tam.mml, tam.mml.2pl and tam.mml.mfr
* cleaned labels in 'tam.mml.mfr' for faceted models
* included the argument 'score.resp' in tam.wle for scoring
  a new dataset different than the one which is used for item
  calibration in tam (requested by Jan Boehnke)
* added examples for applying a sum constraint of item
  parameters in 'tam.mml' (request by Kelvin Gregory)
* included argument 'adj' in tam.jml/tam.jml2 for modifying 
  the adjustment in case of perfect scores (thanks to Courtney Castle)
* included dataset 'data.timssAusTwn.scored'
* included summary for tam.jml
* use plausible values for calculation in item fit (in tam.mml.fit)
* included an example for creation of user-defined fit statistics

-------------------------------------------------------------
CHANGES IN VERSION 0.9 (2013-10-13)  --  CRAN 0.99-9
-------------------------------------------------------------

* removed blanks in item category labels in tam.ctt2 and 
  tam.ctt3
* allowed non-integer group labels
* fixed a bug in data preparation for facet models 
  which appeared since a change in TAM 0.7 
  (thanks to Jonathan Williams)

-------------------------------------------------------------
CHANGES IN VERSION 0.8 (2013-10-02)  --  CRAN 0.8-19
-------------------------------------------------------------

* changed rating scale parametrization for unequal
  number categories per item
* included a warning in tam.ctt2 if memory allocation is
  reached
* included deviance plot 'plotDevianceTAM' 
  (thanks to Sebastian Weirich)
* included tam.ctt3

-------------------------------------------------------------
CHANGES IN VERSION 0.7 (2013-09-15)  --  CRAN 0.7-35
-------------------------------------------------------------

* include crossprod in some functions
* fixed a bug for using latent regression models in
  facet model function 'tam.mml.mfr'
  (thanks to Jonathan Williams)
* included another facet example (Example 14)
* fixed a bug in tam.mml.mfr if all facets possess
  the same number of levels
* fixed a bug in multidimensional generalized partial
  credit model estimation and speeded 2PL estimation a bit
* included bifactor model and exploratory factor analysis
  -> function 'tam.fa' with arguments irtmodel='efa','bifactor'
* now printing progress in tam.ctt2 correctly
* fixed a bug in data processing in tam.mml.mfr for factor
  or string input of facets
* included more examples in tam.fit, anova.tam.mml, tam.pv,
  tam.jml, tam.se, tam.wle 
* avoided inversion of singular matrices in multidimensional
  WLE estimation tam.wle (thanks to Iasonas Lamprianou)
* removed bugs for item response datasets with only one item
  in tam.mml and tam.mml.2pl
* fixed a bug in tam.ctt2: multiple groups were not displayed 
* included an option for deleting redundant generalized items
  which sometimes improves computation speed
* cleaned the TAM manual (thanks to Michaela Mayr)
* changed output structure of tam.fa and included rotation
  examples in tam.fa.Rd
* included additional convergence stabilizing approach which
  can be activated using the argument 'fac.oldxsi' in control
  -> See Example 15 for such a non-converging model where
     changing algorithmic defaults seems necessary
   (problem addressed thanks to Sebastian Weirich) 
* substituted internal 'theta.sq' function by Rcpp based
  function 'theta.sq2'
* started with including examples similar to the ones in
  the ConQuest 2.0 manual (see data.cqc.Rd)

-------------------------------------------------------------
CHANGES IN VERSION 0.6 (2013-08-28)  --  CRAN 0.6-26
-------------------------------------------------------------

* fixed a bug when in latent regression when providing a formula
  in argument 'formulaY'
* fixed a bug in output of tam.se (thanks to Sebastian Weirich)
* included a faster alternative to tam.ctt -> tam.ctt2 is based
  on a Rcpp function
* allowed freeing beta constraints by the user by including
  the possible argument beta.fixed=FALSE
* removed a bug in data processing for faceted designs
  (thanks to Michaela Mayr)
* fixed a bug with varying string lengths of facet levels
* fixed a bug in tam.ctt2 for numeric input matrices
* fixed incorrect handling of constraints in regression coefficients
  which was just included in a recent 0.6 version
* fixed an output bug in tam.wle in multidimensional models
  (thanks to Jan Henning-Kahmann)
* accelerated estimation of multdimensional models (different
  approach of calculating the prior distribution)
* fixed a bug when submitting xsi.inits and beta.inits to tam
* fixed a bug in facet models when a facet contains only one
  element (twice thanks to Michaela Mayr)
* included irtmodel='PCM2' (partial credit model with ConQuest
  parametrization) and irtmodel='RSM' (rating scale model)
* added a longitudinal data example in 'tam.mml' manual

-------------------------------------------------------------
CHANGES IN VERSION 0.5 (2013-07-28)  --  CRAN 0.5-21
-------------------------------------------------------------

* included data.ex11 example dataset
* removed a bug in WLE calculation for multifaceted designs
* avoided warning in cov2cor for tam.mml.2pl function
  (thanks to Linda Graefe)
* included argument increment.factor for obtaining
  convergence behavior in bad suited data constellations
* changed default of np.adj in tam.pv to 8
* included two helper functions written in Rcpp in
  plausible value imputation function tam.pv for
  better performance
* included S3 plot method
* included data.numeracy and data.timssAusTwn datasets

-------------------------------------------------------------
CHANGES IN VERSION 0.4 (2013-07-01)  --  CRAN 0.04-43 
    [*** First CRAN Release ***]
-------------------------------------------------------------

* included quasi-Monte Carlo integration as an alternative
  to stochastic integration
* multifaceted model completely implemented
* print warning if there are items in resp with only zeroes
  (thanks to Ronny Scherer)
* fixed a bug in tam.wle, tam.pv and tam.se
* fixed a bug in creating design matrices for faceted designs
* changed initial xsi values for indetermined parameters
  (thanks to Sebastian Weirich)
* included function for calculating Thurstonian thresholds
* included Rcpp function in M step for calculating item parameters
* fixed a bug for partial credit models
* included parametrization of the dispersion model for ordered data
* included a function tam.ctt for calculating some statistics
  based on classical test theory
* fixed a bug in tam.mml.2pl with irtmodel="GPCM" for models
  with differering numbers of item categories

-------------------------------------------------------------
CHANGES IN VERSION 0.3 (2013-03-23)
-------------------------------------------------------------

* cleaned Rd manual files a bit
* included standard errors in tam.mml and tam.mml.2pl
* included summary.tam and summary.tam.mml
* included anova.tam for model comparisons
* fixed a bug in multiple group estimation during tam.mml and
   summary application
* fixed a bug in WLE estimation in the multdimensional case

-------------------------------------------------------------
CHANGES IN VERSION 0.2 (2013-02-20)
-------------------------------------------------------------

* removed bugs in tam.pv for sampling plausible values
  with the argument normal.approx=FALSE 
  (thanks to Sebastian Weirich)
* included seed for stochastic integration in the tam
  control argument
* fixed a bug in stochastic integration
  (thanks to Steffen Brandt)
* fixed a bug in the calculation of reliability and person
  parameter estimates when applying stochastic integration
  (thanks to Steffen Brandt and Caroline Just)
* use estimated parameters with minimal deviance in the output
  (thanks to Ulrich Schroeders and Steffen Brandt)

-------------------------------------------------------------
CHANGES IN VERSION 0.1-03 (2012-11-21)
-------------------------------------------------------------

* 2PL calibration outsourced
* designMatrices and tam.mml.mfr method for multifacet rasch model 
  calibration included. Both highly experimental.
* Examples for the calibration included, see help file of sim.mfr
 
