Multiple choice results are inherently probabilistic outcomes, as correct responses reflect a combination of knowledge and guessing, while incorrect responses additionally reflect blunder, a confidently committed mistake. To objectively resolve knowledge from responses in an MC test structure, we evaluated probabilistic models that explicitly…

This study proposes and examines an analytical method with the aim of improving the quality of education and learning by situating the answers to full descriptive questions in probability and statistics to make variables of learners' comprehension of learned content as answer characteristics, based on actual student mistakes. First, we proposed…

This study investigated how population parameters representing heterogeneity of variance, skewness, kurtosis, bimodality, and outlier-proneness, drawn from normal and eleven non-normal distributions, also characterized the ranks corresponding to independent samples of scores. When the parameters of population distributions from which samples were…

Florida requires that students who do not meet grade-level reading proficiency standards on the end-of-year state assessment (Florida Comprehensive Assessment Test, FCAT) receive intensive reading intervention. With the stakes so high, teachers and principals are interested in using screening or diagnostic assessments to identify students with a…

Orlando and Thissen (2000) developed an item fit statistic for binary item response theory (IRT) models known as S-X[superscript 2]. This article generalizes their statistic to polytomous unfolding models. Four alternative formulations of S-X[superscript 2] are developed for the generalized graded unfolding model (GGUM). The GGUM is a…

College Level Examination Program (CLEP) Tests were normed on a national basis, administering the test to nationwide samples of subjects. Norms appear in the booklet, CLEP Scores: Interpretation and Use, and consist of the test score means for groups of students receiving grades of A, B, C, D, and F in the relevant course, the proportion of…

This chapter provides an overview of statistical issues arising in work on educational assessment and school accountability, organized around some of the most consequential misunderstandings. The article proceeds via a series of nine vignettes describing misunderstandings of statistical uncertainty in educational assessment and school…