As it is my understanding that the ltm-package is obsolete, I'm looking for an equivalent to ltm::unidimTest() in the mirt-package.
I'm quite new to IRT-Models, so I would be thankful if someone could give me a short breakdown on how to test unidimensionality of polytomous data (likert-scale).
Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) are not sufficiently reliable in my case (Ziegler & Hagemann, 2015).
Thank you!
