Implementing a New Score Scale for the Clinical Science Subject Examinations: Validity and Practical Considerations

Prior to August 2015, the National Board of Medical Examiners' (NBME) clinical science subject examination scores were reported as a scaled score. However, the scaled scores had some undesirable properties that threatened the validity of the inferences that score users were making based on the scores. The NBME changed the score scale to equated percent correct scores to address score validity concerns and to better meet the needs of medical school faculty and students. This paper describes the validity and practical considerations associated with the implementation of equated percent correct scores for the clinical science subject examination program.