Researchers frequently evaluate rater judgments in performance assessments for evidence of differential rater functioning (DRF), which occurs when rater severity is systematically related to construct-irrelevant student characteristics after controlling for student achievement levels. However, researchers have observed that methods for detecting…

English language learners are a growing demographic in secondary, two-year, four-year and research institutions where many students encounter their first course in statistics. In the statistics education literature, recent calls have been made to improve statistical education for underserved student populations, including English Language Learners…

The concept of variability is central to statistics. In this research report, we review mathematics education research on variability and, based on that review and on feedback from an expert panel, propose a learning progression (LP) for variability. The structure of the proposed LP consists of 5 levels of sophistication in understanding…