The second time around: accounting for retest effects on oral examinations

Years of research with high-stakes written tests indicates that although repeat examinees typically experience score gains between their first and subsequent attempts, their pass rates remain considerably lower than pass rates for first-time examinees. This outcome is consistent with expectations. Comparable studies of the performance of repeat examinees on oral examinations are lacking. The current research evaluated pass rates for more than 50,000 examinees on written and oral exams administered by six medical specialty boards for several recent years. Pass rates for first-time examinees were similar for both written and oral exams, averaging about 84% across all boards. Pass rates for repeat examinees on written exams were expectedly lower, ranging from 22% to 51%, with an average of 36%. However, pass rates for repeat examinees on oral exams were markedly higher than for written exams, ranging from 53% to 77%, with an average of 65%. Four explanations for the elevated repeat pass rates on oral exams are proposed, including an increase in examinee proficiency, construct-irrelevant variance, measurement error (score unreliability), and memorization of test content. Simulated data are used to demonstrate that roughly one third of the score increase can be explained by measurement error alone. The authors suggest that a substantial portion of the score increase can also likely be attributed to construct-irrelevant variance. Results are discussed in terms of their implications for making pass-fail decisions when retesting is allowed. The article concludes by identifying areas for future research.