Derivational morphology (DM) and how it can be assessed have been investigated relatively rarely in language learning and testing research. The goal of this study is to add to the understanding of the nature of DM knowledge, exploring whether and how it is separable from vocabulary breadth. Eight L2 (second or foreign language) English DM…

Research on assessing English as a foreign language (EFL) development has been growing recently. However, empirical evidence from longitudinal analyses based on substantial samples is still needed. In such settings, tests for measuring language development must meet high standards of test quality such as validity, reliability, and objectivity, as…

Language tests are useful for many purposes, including monitoring language learning progress and evaluating language programs. This study investigated the interpretations and usefulness of the American Council on the Teaching of Foreign Languages (ACTFL) Oral Proficiency Interview -- Computer (OPIc) scores across four languages at a large US…