NBME Internal Medicine Shelf score interpretation?

[440117]

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Hey,
Wrote the NBME Subject Examination Program - Medicine Examination in the last week of October 2011. While I got my scaled score, that's all we got. They didn't tell us what percentile we were in, either for this writing or even compared to last year. The preamble to the document states that:

The subject examination score is scaled to have a mean of 70 and a standard deviation of 8 for a scaling group of first-time takers from U.S. LCME-accredited medical schools who took this examination as a final clerkship examination

It doesn't state that it was normally distributed, but given the huge numbers of test-takers and the very scientific way in which the test is administered, analyzed and marked, you would expect a fairly normal curve. If that were the case, I could calculate my percentile using a calculator like this: http://bayes.bgsu.edu/nsf_web/jscript/normal_cdf/normal_icdf.htm

I'm just not sure if I should be doing that. Does anyone have any information about what marks on this administration correspond to what percentiles, or how to best calculate your approximate percentile? I've seen PDF documents that state very explicitly the percentile that a given scaled score corresponds to. This is one example. THat one is for the internal sub-internship though, not the internal clerkship shelf exam, and I haven't been able to track that down. If anyone knows how I could find one (it would likely be from last year's round of exams) I'd be very grateful.

It just sorta sucks having this mark that doesn't correspond to a raw score OR a percentile. It's essentially useless, aside from telling you that you passed and whether you did better or worse than average. Since it was my first shelf I'd like to know if my study habits are getting me to my goals and knowing my percentile would help.

 

[thesauce]

Hey,
Wrote the NBME Subject Examination Program - Medicine Examination in the last week of October 2011. While I got my scaled score, that's all we got. They didn't tell us what percentile we were in, either for this writing or even compared to last year. The preamble to the document states that:



It doesn't state that it was normally distributed, but given the huge numbers of test-takers and the very scientific way in which the test is administered, analyzed and marked, you would expect a fairly normal curve. If that were the case, I could calculate my percentile using a calculator like this: http://bayes.bgsu.edu/nsf_web/jscript/normal_cdf/normal_icdf.htm

I'm just not sure if I should be doing that. Does anyone have any information about what marks on this administration correspond to what percentiles, or how to best calculate your approximate percentile? I've seen PDF documents that state very explicitly the percentile that a given scaled score corresponds to. This is one example. THat one is for the internal sub-internship though, not the internal clerkship shelf exam, and I haven't been able to track that down. If anyone knows how I could find one (it would likely be from last year's round of exams) I'd be very grateful.

It just sorta sucks having this mark that doesn't correspond to a raw score OR a percentile. It's essentially useless, aside from telling you that you passed and whether you did better or worse than average. Since it was my first shelf I'd like to know if my study habits are getting me to my goals and knowing my percentile would help.

Assume a normal distribution. The calculator you posted should be pretty accurate.

 

[ijn]

Assume a normal distribution. The calculator you posted should be pretty accurate.

Can you really assume a normal distribution or does it really matter? You'd figure the NBMEs might look something like STEP. For example something like this that has a long tail:

 

[DrBowtie]

Can you really assume a normal distribution or does it really matter? You'd figure the NBMEs might look something like STEP. For example something like this that has a long tail:

Is that from their self reported sample?

 

[winkleweizen]

Hey,
Wrote the NBME Subject Examination Program - Medicine Examination in the last week of October 2011. While I got my scaled score, that's all we got. They didn't tell us what percentile we were in, either for this writing or even compared to last year. The preamble to the document states that:



It doesn't state that it was normally distributed, but given the huge numbers of test-takers and the very scientific way in which the test is administered, analyzed and marked, you would expect a fairly normal curve. If that were the case, I could calculate my percentile using a calculator like this: http://bayes.bgsu.edu/nsf_web/jscript/normal_cdf/normal_icdf.htm

I'm just not sure if I should be doing that. Does anyone have any information about what marks on this administration correspond to what percentiles, or how to best calculate your approximate percentile? I've seen PDF documents that state very explicitly the percentile that a given scaled score corresponds to. This is one example. THat one is for the internal sub-internship though, not the internal clerkship shelf exam, and I haven't been able to track that down. If anyone knows how I could find one (it would likely be from last year's round of exams) I'd be very grateful.

It just sorta sucks having this mark that doesn't correspond to a raw score OR a percentile. It's essentially useless, aside from telling you that you passed and whether you did better or worse than average. Since it was my first shelf I'd like to know if my study habits are getting me to my goals and knowing my percentile would help.

We get our scores and percentiles....and 70 is NEVER the average. I think for my last couple of shelfs the averages have been 74 and 75 nationally.

 

[thesauce]

You can assume normal distribution or a skew, but you'll never know which it is so might as well make it easy on yourself.

 

[gravitywave]

You can assume normal distribution or a skew, but you'll never know which it is so might as well make it easy on yourself.

i approve of this post 👍

 

[SirGecko]

We get our scores and percentiles....and 70 is NEVER the average. I think for my last couple of shelfs the averages have been 74 and 75 nationally.

They tell you the average score and standard deviation on the score report and it was 70 with a sd of 8 on the medicine shelf. (from test in December)

 

[FSU2013]

They tell you the average score and standard deviation on the score report and it was 70 with a sd of 8 on the medicine shelf. (from test in December)

That's not exactly accurate. The average of 70 was designated when the test was designed (over a decade ago). Because of this, the annual average perpetually rises......there really isn't a way to figure out you're percentile from that number.