Exploring assessor cognition as a source of score variability in a performance assessment of practice-based competencies.

This study provides insight into the nature and extent of assessor variability during a performance assessment of practice-based competencies. Study findings are interpretable from the measurement and contextual perspectives on assessor cognition. An integrated understanding is important to elucidate the meaning underlying the numerical score because the defensibility of inferences made about students' proficiencies rely on score quality, which in turn relies on expert judgements.