My Hippocampal Vehemence!!!!

Recently quiet a few of my juniors have been calling up, few of them have got their step 1 scores the others plan to sit for coming slots, but interesting part is that a lot of confusion prevails among a myriad of things on the scores and their interpretation. Today in this blog I shall take up the scores and what it reflects.

The score report that we receive has two numbers on it – a 3 digit score and a 2 digit score. So does it call for a rejoice when I get a 99 as my two digit score, well if you want you may but the fact is that it is not a percentile score as it is commonly referred to. I told this bluntly, the only saving grace was that the person talking to me was on the phone, the next question- what is it? ….Well even if its not a percentile it is definitely a good score (that brings a smile back on his face, I guess so).

No its neither the percentage, let us begin understanding the exam: you attempt 350 questions which entitles you to a maximum score of 300(yes and not 350). The National Board of Examiners has not yet made it clear as to how do they interpret your scores. The score (3 digit) is obtained from your performance in the actual exam, then comes the next step where your performance is compared with the examinees in the previous 3 month slot and the score is also evaluated against the average of native US examinees.

This is how 3 digit score is awarded. The maximum score is 300 and that required for passing is 182. Once the 3 digit score is done ur 2 digit score is computed which is a reflection of the 3 digit score. The passing score is 75 and this cannot logically be a percentage because 75% of 300 is 225, while a score of 75 corresponds to 3 digit score 182.

It is also not percentile because a percentile means in very crude terms no of test takers that have been bettered by you. This is unlike a CAT score where 99 means your score is better than 99% of CAT exam takers that year. To understand this we’ll turn back to the score card, the national board mentions mean score and standard deviation for every slot. Which typically remains as 212-220(mean score) and 20-26(standard deviation). So, when I get a 239/98 what does it mean? Assuming the mean score is 218 and the standard deviation is 20 then this score is 239-218= 21 marks more than the mean score, we obtain the Z score as follows 21/SD= 21/20= 1.05 this means the score 239 was 1.05 standard deviations above the mean score of 218 this corresponds to a value of 0.3531+0.5= 0.8531 or 85 percentile this is certainly not 98 percentile (and I thought I was better than 98% junta).

These distortions and constraints make the 2-digit score an unjust system to rank test-takers and today, most residency programs use the 3-digit score to compare people. Because the 3-digit to 2-digit scale conversion changes every year, it makes sense to stick to the 3-digit scale which makes comparisons between old-timers and new-timers possible.

Anyways 99 percentile in USMLE is no cake walk but yes a 2 digit score of 99 is a job done good, at a score of 245 you get a 99 2 digit so do u get at 277!!!....isn’t it Amazing!!!

….with these insights into USMLE scores I hope you can better evaluate your as well as your friends actual performance, so my advice get out of this high of a 99 score and start preparing for the next step ….best of luck!!!!