Developing a video-based method to compare and adjust examiner effects in fully nested OSCEs.

Despite typical reliability, the examiner cohort that students encountered had a potentially important influence on their score, emphasising the need for adequate sampling and examiner training. Development and validation of VESCA may offer a means to measure and adjust for potential systematic differences in scoring patterns that could exist between locations in distributed or national OSCE examinations, thereby ensuring equivalence and fairness.