How are shelf exams scored?

[vyparik1]

Does anybody know how the shelf exams are scored? I took my surgery shelf on Friday. 100 questions. So, out of 100, will the raw number of questions correct become my percentage or is it scored like the USMLE step 1 where nobody knows??

thanks,

V

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[TulaneKid24]

Originally posted by vyparik1
Does anybody know how the shelf exams are scored? I took my surgery shelf on Friday. 100 questions. So, out of 100, will the raw number of questions correct become my percentage or is it scored like the USMLE step 1 where nobody knows??

thanks,

V

I was wondering the same thing! BUMP

 

[yaah]

I can only speak from my own experience - I think they are scored on percentile with others taking it - not on % you got right. I say this because I got a 99 on my surgery and medicine tests and I am assuming I got more than one wrong on each. I don't think I necessarily deserved those scores, as I assume there are people out there who did get them all right (random chance alone would suggest that possibility). I can't figure out the scoring either. Perhaps each school scores them differently?

Wait - here is some info: It is listed as applying for a biochemistry shelf exam, but probably is valid.

http://www.ttuhsc.edu/som/courses/biochem/1Lowdown.html

"Your grade will be determined by a formula that is the same for all courses in the curriculum, including the clinical clerkships. The NBME reports to us a scaled score between 40 and 100 with the average set at 70. These numbers don't correlate with any other scoring system including the USMLE Step I scores, so don't even try to make sense out of it. The two important scores are the national average of 70 and the failing score of 58 (determined by the NBME as 1.5 standard deviations below the mean). Our standard formula equates a 58 with a GRADE of 70 and it equates a score of 70 with a GRADE of 83. Last year nobody at Texas Tech failed the Biochemistry NBME, although several were close. The year before, only one student failed. Most students perform about the same as they do on the block exams, but it is not uncommon for students who have corrected earlier deficiencies to raise their score substantially. "

and

"Remember that you can throw away quite a few questions and still score above national average. The NBME estimates that between 55 and 60% correct on the raw score will equate to a 70 (mean) scaled score. One student left 20 answers blank when time was called and still got a grade of 83. The message here is don't obsess over every question. There is clearly a limit to this strategy, but moving on to questions you can answer with certainty will raise your chances of a good grade. "

So it sounds like it is not based on percentiles, more like an overall curve of results. Thus, should be lots of 99s out there.

 

[Al Pacino]

If the above information is correct, the mean is a 70 and the standard deviation would be 8. (According to the post, a score of 58 is 1.5 standard deviations below mean, so the SD is 8.)

So...if someone scores a 99, they would be 3.625 standard devations above the mean. That doesn't make much sense to me 🙁

Also, how can someone miss 20 questions and still get an NBME score of 83, which is 1.625 SD above mean 🙁 🙁

 

[Idiopathic]

Originally posted by Al Pacino
If the above information is correct, the mean is a 70 and the standard deviation would be 8. (According to the post, a score of 58 is 1.5 standard deviations below mean, so the SD is 8.)

So...if someone scores a 99, they would be 3.625 standard devations above the mean. That doesn't make much sense to me 🙁

Also, how can someone miss 20 questions and still get an NBME score of 83, which is 1.625 SD above mean 🙁 🙁

3.625 SD above the mean pretty much correlates with 99 to me. 2 SD above the mean correlates with 97.5, so...

And the answer to your second question is that it is based on the performance of other people, which means anything goes, especially if the average is 42 questions wrong (out of 100)

 

[doc05]

shelf exams are scored by the NBME. They will give your school a raw score/percentile. Your clerkship director decides how to scale the scores based on how your classmates did, as well as how much weight to put on the exam, compared with your evaluations, oral exams, etc.

 

[Blade28]

We just took our Internal Medicine shelf a couple weeks ago, and got the results back a few days ago. All we were told was our scaled score, not the raw score.

 

[Airborne]

Shelf exams are scored based on the the national mean (which is made to be ~70) and the national STD (which is usually ~8) -

Regardless of this, i would sincerely encourage you to find out how your final grade is determined - (If one is so inclined).

Indeed, in my school, the MOST that a shelf exam was considered was 20% (OB) and the least 0% (Medicine, that's right - you just had to take it, - and need not Pass it! - the entire grade was subjective from preceptors and residents input!) -

In the end, however, what one should really come out with in a rotation is the ability to identify and treat BASIC problems in a given specialty.

Yes, I know that this isn't always measured by the shelf exams, but I can assure you (or at least I hope as an MS IV) that this is the case and one will not miss the basics as they present in the ED or in clinical practice. Once at the intern level the insight to uncertainty often falls upon the first in line to see the patient which often falls upon the PGY-1 level (no disrespect to us med students out there!) - and in many cases this is not far away from the rotation that one would have taken in med school!.

Regardless.... (and best of luck on the exams!)

Kind regards,

Airborne

 

[Airborne]

As a side note -

And although this may not be the thread to brings this up!

I was once told by an attending that when you enter clincal practice (many years in the future!) - you will be judged on three things - and in this order:

1) Affabilty
2) Availability
3) Ability

Although I was a bit reluctant to listen to this advice it was said to me that once you finish residency, it will be assumed that you know your **** - thus ability becomes less of an issue -

As a referring Doc - you want someone who you can get along with...

Thus Affability becomes an important issue.

In the end, Availability lies somewhere in the middle...

Regardless, something definitely to think about - And I can defintely say that shelf exams do not account for this factor.

Kind regards,

Airborne

 

[Blade28]

In our medicine rotation, you had to get an 80 on the shelf to even be considered for honors. 🙁 Our program only has three grades: honors, pass and fail.

 

[sanfilippo]

It's school-dependent. Here each department sets an MPL (minimum pass level). One-third of your overall clerkship grade comes from the shelf score and two-thirds comes from your composite clinical performance (average of all the evaluations that are submitted for you, the student). This break-down is used by all the departments to be more uniform but some other schools have departments that vary the contributing percentages.

-S.