Changes in Version 0.15-4

  o Updated the "raschtree" vignette ('Using the raschtree function for detecting
    differential item functioning in the Rasch model'). This vignette now also
    includes a section regarding stability assessment via the stablelearner
    package (>= 0.1-3).


Changes in Version 0.15-3

  o Added "IGNORE_RDIFF" flags in some examples in order to avoid showing
    diffs due to small numeric deviations in some checks (especially on CRAN).


Changes in Version 0.15-2

  o The method behind mpttree() has now been published by 
    Behavior Research Methods, see doi:10.3758/s13428-017-0937-z

  o The predict() method for "bttree" objects works again correctly for
    type = "parameter" (previously called type = "worth") and type = "rank".
    Thanks to Heather Turner for pointing out the problem.

  o node_btplot() used to fail for worth=FALSE or ref=<character> but works
    now correctly again. Thanks to Heather Turner for pointing out the problem.
    Also ref=<character> now either matches to <object>$labels or (if not available)
    to colnames(<coefficients>) to facilitate usage with the PlackettLuce
    package.

  o node_regionplot() now also works correctly on devices with a default white
    (rather than transparent) background such as png or jpeg.

  o node_* panel functions gained bg = "white" argument to enable different
    background filling color.


Changes in Version 0.15-1

  o The recently added mpttree() function is now accompanied by a working
    paper, see citation("psychotree") or ?mpttree for details.

  o Properly imported grDevices in NAMESPACE.

  o Basil Abou El-Komboz changed his name to Basil Komboz.


Changes in Version 0.15-0

  o New function mpttree() and visualization function for model-based
    recursive partitioning of multinomial processing tree (MPT) models. These
    functions are somewhat experimental, and their user interface might change
    in future releases.


Changes in Version 0.14-0

  o Internals of package psychotree completely reorganized to employ
    the recent additions and changes in psychotools (>= 0.3-0) and
    to use the new partykit (>= 0.2-0) implementation of the mob()
    function (rather than the old party implementation).

  o The handling of argument 'ref' when producing a region/effect
    plot was changed. Whereas in the previous implementation,
    the restriction specified in this argument was applied to
    the cumulative absolute item threshold parameters, it now is
    applied to the absolute item threshold parameters.

  o New panel-generating visualization functions 'node_profileplot'
    and 'node_regionplot' have been added which replace the old 
    functions 'node_raschplot' and 'node_effects'. 


Changes in Version 0.13-0

  o New functionality for recursive partitioning of partial credit
    and rating scale models via functions pctree() and rstree(),
    respectively. These require package "psychotools" >= 0.2-0
    which provides the corresponding basic model fitting tools.


Changes in Version 0.12-3

  o Improved Depends/Imports/Suggests declarations in
    DESCRIPTION.


Changes in Version 0.12-2

  o Adjusted vignette 'raschtree' according to the slightly 
    different results due to the new approximation 
    formulae for p values in the supLM test used in 
    party::mob() (>= 1.0.3).

  o Improved the package's tests by adding reference output for
    the examples and vignette for comparison checks.


Changes in Version 0.12-1

  o Moved all base functionality to the new "psychotools" package
    in order to provide common infrastructure for both
    "psychotree" and "psychomix" as well as other packages.
    This affects the "paircomp" class and associated methods as well
    as the model fitters btReg.fit() and RaschModel.fit() and
    associated methods.

  o The data sets Firstnames, GermanParties2009, and Soundquality
    have also been moved to psychotools.


Changes in Version 0.11-1

  o Enhanced raschtree() functionality, introduced in detail
    in the new vignette("raschtree", package = "psychotree").
  
  o Added subsample from SPIEGEL Studentenpisa (SPISA) quiz
    for students from Bavaria that answered the same set of
    questions.
    
  o Added artificial data set DIFSim exhibiting differential
    item functioning, employed for illustrating Rasch trees.
    

Changes in Version 0.9-1

  o Added raschtree() function, based on simple RaschModel()
    (for binary 0/1 items).

  o Some bug fixes (subsets with missing drop = FALSE) for paircomp()
    and bttree() with only two objects
    

Changes in Version 0.9-0

  o First CRAN release of the package accompanying the forthcoming
    paper "Accounting for Individual Differences in Bradley-Terry
    Models by Means of Recursive Partitioning" by Strobl, Wickelmaier,
    and Zeileis, accepted for publication in Journal of Educational
    and Behavioral Statistics.
    
  o Compared to earlier package versions available from R-Forge,
    this package does not depend on data/code from the "prefmod2"
    package. All required functionality (basic Bradley-Terry
    regression, paircomp class, data sets) are now contained in the
    "psychotree" package.
