The omega (?) statistic is reputed to be one of the best indices for detecting answer copying on multiple choice tests, but its performance relies on the accurate estimation of copier ability, which is challenging because responses from the copiers may have been contaminated. We propose an algorithm that aims to identify and delete the suspected…

Differential gender performance in standardized mathematics assessment has long been a heated topic. Gender gaps of varied magnitude have been identified on large-scale assessments in the United States. To continue the investigation, this study examined male and female performance on the Programme for International Student Assessment (PISA) 2003…

Differential item functioning (DIF) analysis is a statistical technique used for ensuring the equity and fairness of educational assessments. This study formulates a new DIF analysis method using the information similarity index (ISI). ISI compares item information functions when data fits the Rasch model. Through simulations and an international…