Tutorial: Rasch and 2PL Model in R

Setup Data Rasch Model Plots Model Identification Note on Item Parameters in eRm Package MML Estimation 2PL Model Model Fit Relative Fit of Rasch and 2PL Model Absolute Fit of the Rasch Model DIF Person Parameters ML MAP and EAP Item and Test Information References Recently, I wrote a summary of some illustrative IRT analyses for my students. Quickly, I realized that this might be of interest to others as well, and I am posting here a tutorial for the Rasch model and the 2PL model in R. [Read More]

Accepted Paper: A New Model for Acquiescence

Today, our paper “A new model for acquiescence at the interface of psychometrics and cognitive psychology” has been accepted at Multivariate Behavioral Research. Therein, I developed together with Daniel Heck a model for acquiescence response style on the basis of item response theory, more specifically IR-tree models, and multinomial processing tree models. This research took a long time but was also great fun, especially the collaboration with Daniel. You will soon find the final paper under publications and at MBR, and the abstract is posted below. [Read More]