startNLR
now handles missing values. Returns error when not enough complete observations are provided.- Arguments in
ggplot2
plotting methods were updated to follow changes in theggplot2
package. - Linetype and its legend appearance in
ggplot2
plotting methods were updated.
- Some typos fixed.
class
handling was updated.
It includes versions 1.3.7-1 - 1.3.7-3
- Option
parameterization = "logistic"
was fixed informulaNLR()
function.
- First version of iteratively reweighted least squares algorithm
was implemented in
difNLR()
,NLR()
, andestimNLR()
functions. coef.difNLR()
,coef.difORD()
, andcoef.ddfMLR()
methods now include delta method for IRT and logistic parameterizations.coef.difNLR()
,coef.difORD()
, andcoef.ddfMLR()
methods now include calculation of confidence intervals.
- Some typos fixed.
- Examples in functions were updated.
- References were updated.
- Output of
estimNLR()
function is now unified viaprint()
method. - Packages CTT, grDevices, methods are no longer imported.
- First version of
predicted.difORD()
to compute predicted values fordifORD
object was implemented.
- Bug in plotting empirical probabilities in
plot.difNLR()
fixed.
THIS IS A CRAN VERSION
- doi in DESCRIPTION file updated.
- doi in help pages were updated.
- CITATION file updated.
- References were updated.
- Empty factor levels were removed from
Data
inddfMLR()
to fix bug when plotting.
- Sandwich estimator for covariance matrix in case that
method = "nls"
was implemented into thevcov()
method for the output of theestimNLR()
function. - Wald test for implemented for the
difNLR()
function. - Sandwich estimator for covariance matrix in case that
method = "nls"
was implemented into thedifNLR()
function via an argumentsandwich = TRUE
.
THIS IS A CRAN VERSION
- Error when covariance matrix cannot be computed for some items in
difNLR()
function was fixed.
- URLs for GH were updated.
THIS IS A CRAN VERSION
- Bug in calculation of standard errors for estimates of
difNLR()
was fixed. - Bug in coefficients of
difNLR()
for non-converged items including naming of parameters was fixed (Reported by Jan Netik). - In case that covariance matrix cannot be computed in
NLR()
, function gives warning andNA
values for covariance matrix and vector of standard errors are returned.
- Confidence intervals were added into
predict.difNLR()
method. - Delta method for alternative parametrization is now applied for whole
covariance matrix in
difNLR()
. - Unnecessary arguments of
plot.difNLR()
,plot.difORD()
andplot.ddfMLR()
were removed. Change of colours/linetypes/shapes/title can be managed using standardggplot2
syntax. plot.difNLR()
now offers possibility to turn off drawing of empirical probabilities using argumentdraw.empirical = FALSE
.plot.difNLR()
now offers possibility to plot confidence intervals for predicted values as offered inpredict.difNLR()
using argumentdraw.CI = TRUE
.- Starting values calculated via
startNLR()
were improved forscore
as matching criterion using argumentmatch
.
- Documentation of the package was updated.
- Some typos were fixed.
- Documentation of main functions was updated:
- S3 methods are now referenced in See Also sections.
- S3 methods are now documented in seperate files.
- CITATION file was updated.
- Formatting was improved.
- Legends in
plot.difNLR()
,plot.difORD()
andplot.ddfMLR()
were unified. - Colors in
plot.difORD()
andplot.ddfMLR()
were changed to blind-color friendly palettes.
THIS IS A CRAN VERSION
- Bug in
plot.difNLR()
was fixed.
THIS IS A CRAN VERSION
It includes versions 1.3.0-1 - 1.3.0-6 and following changes:
- Method
plot.difNLR()
now correctly uses matching criterion when item purification is applied.
- Documentation of the package was updated.
- Some typos were fixed.
- NEWS file is now generated using
markdown
. - README file was updated.
- Mismatch in null and alternative models was fixed for all functions.
MLR()
function now returns correct value of log-likelihood for alternative model.
- Default option of argument type in
NLR()
function was set to"all"
instead of"both"
. - Input
Data
indifNLR()
function can be also a vector now.
- Function
MLR()
was fixed for binary data and IRT parametrization. - Typo fixed in
print.difORD()
method. - Method
plot.ddfMLR()
was fixed for binary data.
- Function
ddfORD()
was renamed todifORD()
.
- Function
genNLR()
with an optionitemtype = "nominal"
returns nominal items as factors with levels presented by capital letters. - Legend for
plot.ddfMLR()
was updated to show P(Y = option) instead of option alone. - README file updated.
- Typos fixed.
- Documentation was updated.
- Authors' details were updated.
- Seed was added for re-calculation of bootstrapped initial values
in
NLR()
estimation.
- Argument
item
for S3 methods ofdifNLR
class can be now name of the column inData
. - Legends in
plot.ddfMLR()
andplot.ddfORD()
were updated. - Some typos were fixed.
- Default option of argument type in
difNLR()
function was set to"all"
instead of"both"
.
- Package
styler
was used to improve formatting of the code. - Package
ShinyItemAnalysis
was added into Suggests. - Figures for README were updated.
- Documentation for all data was updated. Format of data was fixed.
- Documentation of
estimNLR()
was improved.
- Legend in
plot.ddfORD()
is now correctly displayed.
THIS IS A CRAN VERSION
It includes versions 1.2.3 - 1.2.8-4 and following changes:
- Some typos fixed in
print.difNLR()
- Authors' details were updated.
- CITATION file was updated.
- Typos fixed in
print.ddfORD()
and print.ddfMLR(). - Matching criterion for
plot.ddfORD()
uses anchor items.
plot.ddfORD()
now works when Data is factor.
genNLR()
now generates ordinal data using adjacent category logit model with argumentitemtype = "ordinal"
.
plot.ddfORD()
now works when items have different scales.- Argument
anchor
is now used for calculation of matching criterion in functionORD()
. - IRT parametrization was fixed for
ddfORD()
. logLik.ddfMLR()
now works properly.- anchor items are now used for calculation of matching
criterion in
plot.ddfORD()
andplot.ddfMLR()
.
- Names of reference and focal group in
plot.difNLR()
can be changed withgroup.name
argument.
- Help pages for
difNLR()
,ddfMLR()
,ddfORD()
,MLR()
, andORD()
functions were updated.
- IRT parametrization now available in
ddfMLR()
function with argumentparametrization
. SE calculated with delta method. - Names of reference and focal group in
plot.ddfMLR()
can be changed withgroup.name
argument.
ddfORD()
function was renamed. NowddfORD()
.- IRT parametrization now available in
ddfORD()
function with argumentparametrization
. SE calculated with delta method. - Names of reference and focal group in
plot.ddfORD()
can be changed withgroup.name
argument.
- Help page for
ddfORD()
was updated. - Reference for
ddfORD()
was added.
- Check for input
item
in S3 methods fordifNLR()
,ddfMLR()
, andddfORD()
was fixed.
- S3 methods
plot()
outputs fordifNLR()
,ddfMLR()
, andddfORD()
functions were unified.
- Help pages were updated.
- README file was updated.
- S3 method
plot()
forddfORD()
was implemented.
- S3 methods
AIC()
,BIC()
,logLik()
,coef()
forddfORD()
were implemented. - S3 methods
AIC()
,BIC()
,logLik()
,residuals()
fordifNLR()
andddfMLR()
objects now handle column names asitem
argument. - S3 method
coef()
fordifNLR
andddfMLR
objects were updated. Their now includes argumentsSE
(logical) to print standard errors andsimplify
(logical) whether list of estimates should be simplified into a matrix.
- CITATION was updated.
- All static DOI links were updated.
- New functions
ddfORD()
andORD()
for DDF detection for ordinal data with adjacent and cumulative logistic regression models were added. Output is displayed via S3 methodprint.ddfORD()
- Authors' details were updated.
- Some typos were fixed.
- Helps for
ddfMLR()
,MLR()
, anddifNLR()
were updated.
plot.ddfMLR()
now handles also binary data.ddfMLR()
returns consistently"No DDF item detected"
when no DDF item was detected.
- Matching criterion for
plot.ddfMLR()
was improved for displaying more smooth curves.
- Authors' details were updated.
THIS IS A CRAN VERSION
It includes versions 1.2.1-1 - 1.2.1-3
- S3 methods
AIC()
,BIC()
,logLik()
ofddfMLR()
are now item specific.
difNLR()
- Check for constraints was fixed.
NLR()
initboot = FALSE
now works properly.
difNLR()
:- P-value adjustment is now performed in the last iteration of purification as described.
- In difPur output columns are properly named.
ddfMLR()
:- P-value adjustment is now performed in the last iteration of purification as described.
- In difPur output columns are properly named.
- Warning messages do not include the call.
THIS IS A CRAN VERSION
It includes versions 1.2.0-1 - 1.2.0-7
- Argument
start
indifNLR()
function is now item-specific. The input is correctly checked. - In case that some items do not converge, starting values are recalculated
from bootstraped sample and problematic models are fitted again. This is done
20 times at most.
The options were added into
difNLR()
andNLR()
functions. - Argument
constraints
indifNLR()
function is now item-specific.
- Minor typos were fixed in
print()
method fordifNLR
class. - Title was shorten.
- Description of package was updated.
- Description file was updated, reference was added.
- README file was updated.
- CITATION file was updated.
- S3 methods for
difNLR
class are now properly described, especially,plot.difNLR()
andpredict.difNLR()
. difNLR()
documentation was improved.
- S3 methods for class
difNLR
can now properly handle items with convergence issues. NLR()
now detects DIF correctly with F test.
- Typos were fixed.
print()
,plot()
,fitted()
,predict()
,logLik()
,AIC()
,BIC()
andresiduals()
fordifNLR
class now handles item specific arguments (model
,type
andconstraints
).residuals
fordifNLR
class now uses argumentitem
.
- Checking inputs in
difNLR
was fixed and improved. - Fixing degrees of freedom and p-values calculations in
NLR()
. - Fixing parameters, SE and covariances calculations in
NLR()
. - S3 methods for
difNLR
class can now handle convergence issues.
- Documentation of
difNLR-package
was updated. - Syntax in
plot()
andresiduals()
fordifNLR
was slightly improved. logLik()
fordifNLR
now returns list oflogLik
class values.
- Function
startNLR()
now handles item-specific arguments (model
andparameterization
). Its output is now in the form of list. It can be simplified with argumentsimplify
into table when all parameterizations are the same. - Function
NLR()
now handles item-specific arguments (model
,type
andconstraints
). - Function
difNLR()
now handles item-specific arguments (model
,type
andconstraints
).
- README file was updated.
- Starting values in input of
estimNLR()
inNLR()
are now properly named. - Bug in alternative parameterization for testing differences in parameters c and d in function
formulaNLR()
was fixed.
- Descriptions of
formulaNLR()
andestimNLR()
were improved.
- Function
genNLR()
can now also generate nominal data based on model specified inddfMLR()
. - Argument
parameters
ingenNLR()
is no longer applicable. - Arguments
a
,b
,c
,d
were added intogenNLR()
as parameters - discrimination, difficulty, guessing, inattention - Function
genNLR()
can now also generate different underlying distributions for reference and focal group with argumentsmu
andsigma
.
- Email address of maintainer was changed.
- New function
estimNLR()
to estimate parameters of NLR models was added. This function uses non-linear least squares or maximum likelihood method. - Function
NLR()
now usesestimNLR()
for estimation of models parameters. - Function
difNLR()
can now estimate models parameters with also maximum likelihood method. - Iteratively reweighted least squares (IRLS) method was added into
estimNLR()
function. This option is not fully functional.
- Bug in
plot()
forddfMLR
class in matching criterion was fixed. - Bug in
NLR()
was fixed. User-specified starting values are now available. - Bug in
startNLR()
was fixed. Function runs even if there are not unique cuts for total scores/match. - Bug in log-likelihood calculation in
estimNLR()
was fixed.
- Some preparation for new estimation methods for F test in
NLR()
was done. - Convergence failure warning is now item specific.
- Warning and error messages were improved.
- Bug in delta method in
NLR()
function was fixed. - Bug in
match
argument indifNLR()
function was fixed. - Bug in one dimensional
Data
indifNLR()
function was fixed.
- Specification of upper and lower asymptotes in
startNLR()
function was improved. - Functions
ddfMLR()
andMLR()
can now handle also total score or other user-specified matching criterion. - S3 functions
plot()
for classddfMLR
can also handle total score or other user-specified matching criterion.
- New auxiliary function
checkInterval()
was added. - Size of labs and title was unified in graphical outputs of functions
difNLR()
andddfMLR()
.
- CITATION file was added with reference to relevant paper.
- Bug when loading group by group identificator was fixed.
- Condition to check dimension of complete cases data was added.
- Function
residuals.difNLR()
was added. - S3 functions
AIC()
andBIC()
fordifNLR
class were updated. - S3 functions
plot()
,fitted()
andpredict()
fordifNLR
class can now handle also other matching criteria thanzscore
.
- Reference lists were updated.
- README file was updated.
THIS IS A CRAN VERSION
- Bug in
startNLR()
function for missing values was fixed.
- Graphical representation for
difNLR()
andddfMLR()
functions was mildly updated and unified.
THIS IS A CRAN VERSION
- Bug in
plot.difNLR()
was fixed. - README file was updated.
- Package documentation was updated.
- Default value for
constraints
arguments inNLR()
andformulaNLR()
functions were set toNULL
. - Default starting values were added into
NLR()
function bystartNLR()
function.
- Several bugs were fixed:
difNLR()
function can handleData
with one column.startNLR()
now works whenmatch
argument is set.- Check input condition was fixed in
formulaNLR()
function. - Delta method in
NLR()
function.
- Function
startNLR()
was mildly updated.
- Item purification was implemented into
ddfMLR()
function. - Anchor items were implemented into
ddfMLR()
function. - Anchor items were implemented into
MLR()
function.
- Minor bug in
logLik.ddfMLR()
function was fixed. - Documentation of
difNLR()
was updated.
- Item purification was implemented into
difNLR()
function. - Anchor items were implemented into
difNLR()
function. - Anchor items were implemented into
NLR()
function.
- README file was updated.
- Datasets
difMedical
,difMedicaltest
, anddifMedicalkey
were renamed. Now they areMSATB
,MSATBtest
, andMSATBkey
. from Medical School Admission Test in Biology.
- LazyData is now available.
- References were updated.
- README file updated.
- New function
formulaNLR()
was implemented. Function returns formula for NLR model for 11 predefined models and 4 predefined DIF types to test. Model and DIF type can be also specified with constraints on parameters a, b, c and d. - Function
NLR()
now handles 11 predefined models and 4 predefined DIF types to test. Model and DIF type can be also specified with constraints on parameters a, b, c and d. - Function
startNLR()
was edited to return starting parameters with different parameterization. It was also mildly changed to correspond to new version ofNLR()
function. - Function
difNLR()
can now handle also total score or other user-specified matching score. - Function
constrNLR()
is no longer part of thedifNLR
package.
- References were updated.
- Some minor bugs were fixed:
- Items are no longer renamed by
difNLR()
andddfMLR()
functions. - Starting values are now correctly checked in
difNLR()
function.
- Items are no longer renamed by
msm
package is now used for delta method indifNLR()
function.
THIS IS A CRAN VERSION
- Bug of
plot.ddfMLR()
for non-uniform DDF was fixed. - References were updated.
THIS IS A CRAN VERSION
- Bug of dimensions for parameter estimates of
difNLR()
function was fixed. - Datasets
GMAT
andGMATtest
were extended bycriterion
variable which is intended to be predicted by test. coef
,logLik
,AIC
andBIC
S3 methods were added for classddfMLR
.
- Functions
plot.ddfMLR()
andplot.difNLR()
were slightly improved. - Updated error and warning handling in
difNLR()
andddfMLR()
functions. - Description file was updated.
- Item names are now the same as in original data set.
- README file updated.
THIS IS A CRAN VERSION
- New function
ddfMLR()
to detect Differential Distractor Functioning (DDF) with Multinomial Log-linear Regression (MLR) model. S3 methods for classddfMLR
also added -print
andplot
. - New function
MLR()
to calculate likelihood ratio statistic for detecting DDF with MLR model. - The
difNLR()
function can handle 6 generalized logistic regression models with optionmodel
. - Functions
startNLR()
,genNLR()
ans S3 methods for classdifNLR
were changed accordingdifNLR()
function. S3 methodcoef
was created. - New functions
NLR()
andconstrNLR()
can now calculates DIF detection statistics and specify constraints for generalized logistic regression model. - Function
difNLR()
was edited to response todifR
package and its DIF detection functions. - Function
genNLR()
was changed to generate dataset from generalized logistic regression model with 8 parameters.
- The CITATION file was updated.
- Several typos were fixed.
- Some default options of input were changed.
AIC()
,BIC()
, andlogLik()
S3 methods added todifNLR()
.
THIS IS A CRAN VERSION
- S3 method
plot
for classdifNLR
was updated. - New option of
test
indifNLR()
function was added. Possible choices are nowF
for F-test andLR
for likelihood ratio test. - Choice of significant level
alpha
was added intodifNLR()
function with default option 0.05. - Six new data sets were added - scored
GMAT
data, its unscored versionGMATtest
and its keyGMATkey
. ScoreddifMedical
data set, its unscored versiondifMedicaltest
and keydifMedicalkey
. - New function
genNLR()
was added to generate scored (binary) data with model bydifNLR
.
- Several typos were fixed.