Rater errors are some of the most significant validity threats to any performance assessment. Veterinary medical education routinely uses raters to assess student performance in a variety of scenarios (e.g., clinical assessments, OSCEs, etc.). The purpose of this "teaching tip" is to introduce veterinary medical educators to the notion of rater error, identify a list of common rater errors, and discuss how these errors can be addressed and minimized so as to produce accurate and defensible measures of student performance.
Keywords: OSCE; clinical assessment; clinical skills; performance assessment; rater errors; validity; veterinary medical education.