Why is a given MCAT section score different percentiles?

[TheBiologist]

for instance, a 127 on biological is 75th percentile but a 127 on CARS is 83rd

why wouldn't they just make them all the same? does this say that people do better on biological compared to CARS?

 

[efle]

Someone more knowledgeable please correct me if I'm wrong, but I think it's got to do with the MCAT subsections being scaled but not normalized. If the distribution of raw percentages correct is different between sections, then the scaled values will be at different percentiles.

I once plotted the percent correct vs percentile for the old test, and it came out showing Bio tended to have higher raw percentages correct. So yeah, in a sense, people do better on Bio.

 

[USERX]

I think it has to do with how many questions that you actually get right in relation to other test takers. There are more percentages in between 0 and 100 than there are between scores of 472 to 528. So there is some variation there as well as variation between grading on sections. CARS is the odd ball. That being said I have never seen that big of a % difference.

 

[efle]

^ Other way around. More correct answers get marked in Bio. So getting X% correct in Bio is less impressive/rare than getting the same X% correct in Verbal. That difference is preserved when you scale and turn "X%" into "Y out of 132", so the final result is that a Y in Bio is less impressive/less rare/lower percentile than a Y in Verbal.

 

[Prometheus123]

Someone more knowledgeable please correct me if I'm wrong, but I think it's got to do with the MCAT subsections being scaled but not normalized. If the distribution of raw percentages correct is different between sections, then the scaled values will be at different percentiles.

I once plotted the percent correct vs percentile for the old test, and it came out showing Bio tended to have higher raw percentages correct. So yeah, in a sense, people do better on Bio.

Makes sense. Probably one reason most of us get into this is that we love bio.