One of the great mysteries of the USMLE was the dichotomous scoring system. Usually, an examinee would be given 2 scores, one a 2 digit score, with the minimum cut off fixed at 75, and a maximum of 99. And the other, a 3 digit score, which was more representative of the overall performance of the student. While the rationale for this system was always a mystery to me, the latest edition of the ECFMG Reporter seems to claim that this was just to satisfy some bureaucratic system, where the state boards required a 2 digit score.
The 3 digit score is not only more representative of the individual’s performance, but also, it is a better scale for comparison of results across time, since this is a more stable system.
With the elimination of the reported 2 digit score, now there will be less confusion regarding scoring system of the USMLE. However, there is a little caveat: the 2 digit score is not being done away with, it will still be reported to the state medical boards. Only the examinee’s transcript will no longer carry the score.
Here is what the ECFMG Reporter has to say on the issue:
CHANGES TO USMLE PROCEDURES FOR REPORTING SCORES
Starting July 1, 2011, USMLE transcripts reported through the ERAS reporting system will no longer include score results on the two-digit score scale. USMLE results will continue to be reported on the three-digit scale. This affects the Step 1, 2 CK, and 3 examinations only; Step 2 CS will continue to be reported as pass or fail. These changes do not alter the score required to pass or the difficulty of any of the USMLE Step examinations.
Since its beginning in the 1990s, the USMLE program has reported two numeric scores for the Step 1, Step 2 CK, and Step 3 examinations, one on a three-digit scale and one on a two-digit scale. The three-digit score scale is considered the primary reporting scale; it is developed in a manner that allows reasonable comparisons across time. The two-digit scale is intended to meet statutory requirements of some state medical boards that rely on a score scale that has 75 as the minimum passing score. The process used to convert three-digit scores to two-digit scores is designed in such a way that the three-digit minimum passing score in effect when the examinee tests is associated with a two-digit score of 75.
The USMLE program requires its governing committees to reevaluate the minimum passing score every three to four years. This process has, at times, resulted in changes in the minimum passing score, expressed on the three-digit scale, and an accompanying change in the score conversion process, to ensure that a two-digit score of 75 is associated with the new minimum passing requirement. A by-product of the adjustment of the score conversion system over time has been a shift in the relationship between the two score scales. This shift has no impact for USMLE score users who use the three-digit scoring scale or for those using the two-digit scale with a primary interest in whether the examinee has a passing two-digit score of at least 75. However, it may create challenges in interpretation for score users who are focusing on two-digit scores, other than 75, and are doing so for purposes of comparing USMLE scores that span several years.
To simplify matters and make interpretation of USMLE information more convenient for score users, the USMLE Composite Committee has asked staff to report two-digit scores only to those score users for whom the scale is intended, i.e., the state medical boards. The Committee also asked that examinees continue to receive scores on both scales so that they are fully informed about the information that will be reported when they ask that results be sent to a state medical board. When examinees request that their results be sent to other score users, only the three-digit score will be reported. Current plans call for these changes to begin with the elimination of the two-digit score from USMLE transcripts reported through the ERAS reporting system starting July 1, 2011. Other systems and procedures for reporting results will be similarly modified as soon as possible after the July 1, 2011 date.