About 45 R packages to analyze data using item response theory (IRT) have been developed over the last decade. This article introduces these 45 R packages with their descriptions and features. It also describes possible advanced IRT models using R packages, as well as dichotomous and polytomous IRT models, and R packages that contain applications…

To control for interactions in learning research due to subjects' prior knowledge of the instructional material presented, an imaginary curriculum was presented with a computer assisted technique based on Carl Berieter's imaginary science of Xenograde systems. The curriculum consisted of a classification system for ten conceptual classes of…

The sequential probability ratio test (SPRT), developed by Abraham Wald, is one statistical model available for making mastery decisions during computer-based criterion referenced tests. The predictive validity of the SPRT was empirically investigated with two different and relatively large item pools with heterogeneous item parameters. Graduate…