Feedback is a powerful instructional tool for motivating learning. But effective feedback, requires that instructors have accurate information about their students' current knowledge status and their learning progress. In modern educational measurement, two major theoretical perspectives on student ability and proficiency can be distinguished.…

"Item models" (LaDuca, Staples, Templeton, & Holzman, 1986) are classes from which it is possible to generate items that are equivalent/isomorphic to other items from the same model (e.g., Bejar, 1996, 2002). They have the potential to produce large numbers of high-quality items at reduced cost. This article introduces data from an…