Qasim Kadhim - English Language Department, Al-Mustaqbal University College, Babylon, Iraq
Safa Abdulridah - University of Warith Al-Anbiyaa, Karbala, Iraq
Dhameer A. Mutlak - Al-Nisour University College/Baghdad/Iraq
Nour Raheem Neamah - Al-Manara College for Medical Sciences (Maysan)/Iraq
Zaidoon Kareem - Department of Medical Laboratory Technics, Al-Zahrawi University College, Karbala, Iraq
Doaa A. Hamad - Nursing Department, Hilla University College, Babylon, Iraq.
Jassim Tuama - Altoosi University College, Najaf, Iraq
Mohammed Qasim - Al-Esraa University College, Baghdad, Iraq

A C-Test is a gap-filling test for measuring language competence in the first and second language. C-Tests are usually analyzed with polytomous Rasch models by considering each passage as a super-item or testlet. This strategy helps overcome the local dependence inherent in C-Test gaps. However, there is little research on the best polytomous Rasch model for C-Tests. In this study, the Rating Scale Model (RSM) and the Partial Credit Model (PCM) for analyzing C-Tests were compared. To this end, a C-Test composed of six passages with both RSM and PCM was analyzed. The models were compared in terms of overall fit, individual item fit, dimensionality, test targeting, and reliability. Findings showed that, although the PCM has a better overall fit compared to the RSM, both models produce similar test statistics. In light of the findings of the study, the choice of the best Rasch model for C-Tests will be discussed.

C-test, Local item dependence, rating scale model, partial credit model, Unidimensionality