This study aimed to compare the efficiencies of multi-dimensional CAT versus uni-dimensional CAT based on the multi-dimensional graded response model and provide information about the optimal size of the item pool. Item selection and ability estimation methods based on multi-dimensional graded...

Assessing IRT model-fit and comparing different IRT models from a Bayesian perspective is gaining attention. This research evaluated the performance of Bayesian model-fit and model-comparison techniques in assessing the fit of unidimensional Graded Response (GR) models and comparing different GR...

One of the sources of inaccuracy in parameter estimates of multilevel models is omitted variable bias, caused by the omission of an important predictor. The purpose of this study was to examine the performance of six estimation procedures in estimating the fixed effects when a level-2...

The purpose of this study was to investigate the performance of Beaton~{!/~}s MR and MSR fit indices for assessing goodness-of-fit of IRT models. These statistics are based on a standardized residual calculated from an expected and observed response. The investigation was conducted using a Monte...

This study evaluated the robustness of DIF detection for multidimensional polytomous items using two different estimation methods, MG-CFA and MGRM-DFIT. A simulation study across 960 study conditions was performed. The purpose of this study was to establish the Type-I error rate and Power of DIF...