Educational assessment data are often collected from a set of test centers across various geographic regions, and therefore the data samples contain clusters. Such cluster-based data may result in clustering effects in variance estimation. However, in many grouped jackknife variance estimation applications, jackknife groups are often formed by a…

Newer statistical procedures are typically introduced to help address the limitations of those already in practice or to deal with emerging research needs. Quantile regression (QR) is introduced in this paper as a relatively new methodology, which is intended to overcome some of the limitations of least squares mean regression (LMR). QR is more…

This article examines the intersection of psychometrics and sociolinguists in the testing of English language learners (ELLs); it discusses language, dialect, and register as sources of measurement error. Research findings show that the dialect of the language in which students are tested (e.g., local or standard English) is as important as…