It is desirable for an educational assessment to be constructed of items that can differentiate different performance levels of test takers, and thus it is important to estimate accurately the item discrimination parameters in either classical test theory or item response theory. It is particularly challenging to do so when the sample sizes are…

Different variants of the selected-response (SR) item type have been developed for various reasons (i.e., simulating realistic situations, examining critical-thinking and/or problem-solving skills). Generally, the variants of SR item format are more complex than the traditional multiple-choice (MC) items, which may be more challenging to test…

In this report, we demonstrate use of differential response time (DRT) methodology, an extension of differential item functioning methodology, for examining differences in how students from different backgrounds engage with assessment tasks. We analyze response time data from a digitally delivered mathematics assessment to examine timing…

Two families of analysis methods can be used for differential item functioning (DIF) analysis. One family is DIF analysis based on observed scores, such as the Mantel-Haenszel (MH) and the standardized proportion-correct metric for DIF procedures; the other is analysis based on latent ability, in which the statistic is a measure of departure from…