News for Package eRm

Changes in Version 1.0-9

• Option to set starting values in MLoef() added (thanks to Rainer Alexandrowicz).

Changes in Version 1.0-8

• Bug in thresholds.eRm() fixed for models fitted with se = FALSE.

Changes in Version 1.0-7

• coef.ppar() exported.

• Standard errors added to theta.table object in person.parameter.eRm.

• NA pattern labelling fixed in summary.ppar.

• Bug in plotICC() fixed.

Changes in Version 1.0-6

• duplicated top-level assingments removed.

Changes in Version 1.0-5

• is.R() in plotCI() removed.

Changes in Version 1.0-4

• Fortran code for matrix sampling updated.

• Bug in item_info() fixed.

Changes in Version 1.0-3

• Bug in person.parameter.eRm() for RSM fixed.

Changes in Version 1.0-2

• NPtest() can now be applied to matrices up to 256 columns (Fortran code changed).

• More flexibility for the legend in plotINFO() added.

• Full and 0 response patterns are not taken into account in SepRel().

Changes in Version 1.0-1

• Legend in plotjointICC now uses proper item labels (and better default colors).

• Corrected item-test correlations added to itemfit.

• Sort option in print method for itemfit added.

Changes in Version 1.0-0

• Additional tests in NPtest() added.

• Toy datasets stored as data frames.

Changes in Version 0.16-0

• PersonMisfit() incl. S3 added.

Changes in Version 0.15-8

• sanity check for missings in split vector in LRtest.Rm() added.

• smoother confidence bands added in plotGOF().

Changes in Version 0.15-7

• LRtest.Rm(): bugfix due to updates in base R.

Changes in Version 0.15-6

• plotGOF(): added arguments x_axis, y_axis, set_par, and reset_par to ease customization of the plot.

• Imports functions from default packages packages, as required by the new CRAN-check.

Changes in Version 0.15-5

• implemented an anova() method for all models (except LLRAs, which have their own: anova.llra). see ?anova.eRm

• added a function to compute separation reliability, as proposed in Wright & Stone (1999; see ?SepRel).

• plotINFO() accepts more arguments via ... (see ?plotINFO).

• fixed a bug in plotPWmap().

• fixed a bug in the internal function get_item_cats() related to NAs (affecting LLRA and item-information functions).

• switched encoding to UTF-8 to avoid problems with diacritics, etc. (e.g., Martin-Löf).

• updated citations.

• general improvements.

Changes in Version 0.15-4

• streamlining some functions, updating the vignette, etc.

• warnings are now treated more consistently and can be suppressed with suppressWarnings()

• the plotGOF() function was revamped and tidied up in a couple of places, e.g.:

  • the plotting order of elements in a non-interactive call has been changed to put confidence ellipses and lines in the background and text in the foreground.

  • the x- and y-limits are now dynamically computed by default, so that confidence regions and ellipses are inside the plotting region.

  • the leading “I” before item numbers has been removed for better legibility.

• moved NEWS to the new fancy NEWS.Rd file/format

Changes in eRm version 0.15-3

• an error in test_info() was fixed.

• eRm now depends on R \geq3.0.0

Changes in eRm version 0.15-2

• an error in Tpbis.stat was fixed.

Changes in eRm version 0.15-1

• a bug in person.parameter() has been fixed that caused the estimation to crash in some cases.

• a bug in thresholds() has been fixed that caused the routine to crash.

Changes in eRm version 0.15-0

• the RaschSampler package has been merged into eRm for convenience (still available as a separate package).

Changes in eRm version 0.14-5

• the package is now byte-compiled by default.

• some statistics added to NPtest(), T7 and T7a removed.

• fixed a bug in plotPWmap().

• fixed the mplot argument in plotting routines.

• fixed the split-criterion "all.r" in LRtest().

• deleted all usages of data() in examples, since eRm uses “lazy data.”

Changes in eRm version 0.14-4

• when calling NPtest(), the RaschSampler can now be controlled more specifically (burn_in, step, seed).

• various improvements and bugfixes for LLRA-related functions.

• person parameter values can be extracted now for all persons using coef(). Additionally, in-/exclusion of extrapolated values (for 0 and perfect scores) can be controlled via the argument extrapolated.

• LRtest now computes standard errors (se = TRUE) by default.

• plotDIF now plots “difficulties” for all models (formerly, “easiness” parameters were plotted for Rasch models).

Changes in eRm version 0.14-3

• minor bug fixed in plotGOF(), where on rare occasions confidence ellipses were plotted together with control lines (spotted by Peter Parker)

• improved labelling in plotjointICC()

Changes in eRm version 0.14-2

• warning regarding group assignment when using median or mean split removed from MLoef()

• modification in NPtest() to split long output lines

• changed the delimiters of plotDIF() confidence intervals to pch = 20 (small bullet).

Changes in eRm version 0.14-1

• new experimental functions to calculate and plot item and test information (by Thomas Rusch)

• bug fixed in the calculation of item and person Infit t and Outfit t (hint from Rainer Alexandrowicz).

• eRm no longer depends on the RaschSampler package. However, it must be installed to use NPtest().

• changed the delimiters of plotDIF() confidence intervals to pch = 20.

Changes in eRm version 0.14-0

• new (wrapper) function LLRA() for fitting linear logistic models with relaxed assumptions including utilities for preparing data (llra.datprep()), setting up (build_W()) and modifying (collapse_W()) design matrices, comparing LLRA models (anova()) and plotting results (plotTR() and plotGR()) (by Thomas Rusch).

• “exact” version of the Martin-Löf test for binary items and arbitrary splits added as method to NPtest().

• in plotGOF() confidence ellipses can now be drawn for subsets of items, optionally using different colours

• new function plotDIF() (by Kathrin Gruber): plots confidence intervals for item parameters estimated separately in subgroups, uses LR objects as input

• adapted the MLoef() function to work with polytomous data and more than two item groups

• error checks in NPtest:

  1. 0/full responses for items meaningless for NPtest,

  2. group in method = "T4" must be of type logical,

  3. specifying all items for T4 gives meaningless results.

• warning regarding group assignment when using median split removed from LRtest() and Waldtest().

• some modifications in plotPWmap(): horizontal plotting, different default plotting symbols, option to change size of plotting symbols

• bug in MLoef() fixed (now using logs in calculating the person contributions)

• eRm now depends on R \geq2.12.0

• Latin1 encoding removed

• bug in plotICC() (always same title) fixed

Changes in eRm version 0.13-0

• LLTM(), LRSM(), and LPCM() work now for repeated measurement designs with treatment groups and missing values.

• Rename vignette to “eRm”.

Changes in eRm version 0.12-2

• new function plotPWmap() to plot Bond-and-Fox style pathway maps for the data by Julian Gilbey. Since calculation of the t-statistics requires calculation of the kurtosis of the standardized residuals, according changes to itemfit.ppar(), personfit.ppar(), pifit.internal(), print.ifit(), and print.pfit().

• plotPImap() patched by Julian Gilbey: length of item.subset did not match the documentation, warning stars did not all appear, pre-calculated person.parameter data can be passed to the function via pp, mis-ordered items can be coloured. some minor bugs fixed.

• the optimizer can be changed to optim() using fitctrl <- "optim" and reset to nlm() (the default) with fitctrl <- "nlm"

• value of LRtest() now contains the list fitobj which contains the model objects according to the subgroups specified by splitcr

• MLoef() no longer supports missing values

Changes in eRm version 0.12-1

• function invalid from package gtools integrated into eRm. eRm no longer depends on gtools.

Changes in eRm version 0.12-0

• for RM(), RSM(), and PCM(): eta parameters are now displayed as difficulty parameters; print() and summary() methods changed accordingly.

• new labeling of eta parameters in RM(), RSM(), and PCM(). they now are labeled according to the estimated parameters for items (RM()), items + categories (RSM()), items x categories (PCM())

• function MLoef() for Martin-Löf-Test added

• df in personfit() and itemfit() corrected

• the logLik() functions now extract the log-likelhood and df into objects of class "logLik.eRm" and "loglik.ppar" with elements loglik and df. the corresponding print methods have been modified accordingly.

• method coef.ppar() to extract person parameter estimates added

• option for beta parameters added to coef.eRm

• in confint.eRm: default parm = "beta"

• minor modifications in the help file for IC()

• plotPImap(): revised rug added, bug concerning item.subset fixed, minor modifications to enhance readability

• minor modifications in plotjointICC(): allows for main title and colors, option legpos = FALSE suppresses legends, dev.new removed, legend = FALSE produced incorrect labeling

• minor modifications in plotICC(): allows for main title and colors, default coloring with col = NULL instead of NA for compatibility, option legpos = FALSE suppresses legends, mplot is now FALSE if only one item is specified

• plot.ppar: dev.new removed

• option “visible” in print.ifit und print.pfit to allow for avoiding overly long output and for extraction of infit and outfit values (maybe changed to a coef method later)

• strwrap() for NPtest print methods to break long lines

• new methods IC.default() and pmat.default() for enhanced error messages

• lazy loading package and datafiles