In a signal detection theory (SDT) approach to multiple choice exams, examinees are viewed as choosing, for each item, the alternative that is perceived as being the most plausible, with perceived plausibility depending in part on whether or not an item is known. The SDT model is a process model and provides measures of item difficulty, item…

W scores are used in a number of commercially available tests. Due to their complex nature, it can be hard for applied researchers and practitioners to understand them or even acquire information about them beyond what is provided in technical manuals. In this article, we provide information regarding the background and derivation of W scores that…

Although the root-mean squared deviation (RMSD) is a popular statistical measure for evaluating country-specific item-level misfit (i.e., differential item functioning [DIF]) in international large-scale assessment, this paper shows that its sensitivity to detect misfit may depend strongly on the proficiency distribution of the considered…

This guide was created as a resource to help families better understand "Measures of Academic Progress"® (MAP®), and their child's results. The guide provides answers to a variety of questions such as: "What is MAP?"; "What does MAP measure?"; "How do schools and teachers use MAP scores?"; "Can MAP tell…

We present evidence that the positive relationship between kindergarten entrance age and school achievement primarily reflects skill accumulation prior to kindergarten, rather than a heightened ability to learn in school among older children. The association between achievement test scores and entrance age appears during the first months of…