On Tue, 9 Dec 2014, Richard M. Heiberger wrote:
I recommend the likert() function in the HH package.install.packages("HH") library(HH) ?likert
I think this only visualizes the polytomous items but provides no formal inference for IRT modeling and DIF testing.
For fitting polytomous IRT models (PCM, RSM, etc.) there are various R packages available, probably most prominently the "eRm" package. This also includes several tests for DIF. But many other approaches are also available (including the "lordif" package). A good first overview is given in the Psychometrics task view on CRAN, see: http://CRAN.R-project.org/view=Psychometrics
hth, Z
On Tue, Dec 9, 2014 at 3:22 AM, munevver kaya <munevver.r...@gmail.com> wrote:Hello, I will analyze polytomous differential item functioning for IRT. I have a Likert type scale. For example, I want to analyze items in term of gender. Is lordifsufficient for this or are there any other packages in R programme? Best Regards, [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
