The proficiency dimension of the learning-oriented assessment (LOA) framework addresses the specific linguistic and content knowledge, skills, and abilities (KSAs) possessed by L2 learners -it is the substance, or the "what" of teaching and learning. It raises questions such as: What do learners know? What are they expected to know? What do they actually know (Turner & Purpura, 2015). Proficiency is often conceptualized through theoretical models of L2 ability, such as Lado's (1961) "Skills-and-Elements" model, Bachman and Palmer's (1996) model of communicative language ability, and Purpura's (2004) conceptualization of L2 Proficiency. These proficiency models attempt to identify how KSAs are situated in the minds of learners. In addition to these models, the proficiency dimension also examines the dynamic role of learner proficiency by asking how KSAs change and may be tracked over time.