The relationship between differential item functioning (DIF) and item difficulty on the SAT is such that more difficult items tended to exhibit DIF in favor of the focal group (usually minority groups). These results were reported by Kulick and Hu, and Freedle and have been enthusiastically discussed by more recent literature. Examining the…

This study investigated the relationship between students' actual performance (accuracy) and their subjective judgments of accuracy (confidence) on selected English language proficiency tests. The unidimensional and multidimensional IRT Rasch approaches were used to model the discrepancy between confidence and accuracy at the item and test level…

Another Rasch approach to the measurement of change, the multidimensional random coefficient multinomial logit model (MRCML), is proposed. The MRCML model can be applied to polytomous items and the investigation of variations in item difficulties. Some simulation studies demonstrate good parameter recovery for the MRCML model under various testing…