"Performing at the 90% level" doesn't mean anything unless you assume that the questions are precisely calibrated so that someone with a good understanding of the material will get about 90% of the questions right in the allowed amount of time. While this is very common in high school, in my five years of college I never took a class that used this scale. Why should you assign problems so easy that someone with almost no grasp of the material gets 60% of them right (D) and a decently smart person who studies a lot can be assured of 100% (A+)?
The question you should be asking is "Is it possible to get the percentage needed for a 5 without a good understanding of the subject?" An exam with five truly difficult problems, where you get a 5 if even one is fully solved, would be a good exam by this standard despite looking very bad by the standard you are using.
I agree that AP exams are often too easy and do not require a good understanding of the material, but
I was very surprised that I scored a 5 (the top mark), because at the time when I took the exam, I didn't know some very basic things that were on the syllabus.
is the only thing in your whole post that's really relevant to this.
I agree that AP exams are often too easy and do not require a good understanding of the material, but [...] is the only thing in your whole post that's really relevant to this.
I also wrote:
"On an object level, based on my experience taking the AP calculus exams as a high schooler, my experience teaching calculus for three years at University of Illinois, and my revisiting the exams, I think that students who score 90% on an AP calculus exam know the material very well, and that students who score 63% (the lowest percentage needed to get a 5) have only marginal knowledge of the material."
When I was in high school, I noticed is that it was possible to score the top mark on an Advanced Placement (AP) Exam by answering a relatively small portion of the questions correctly.
During my junior year, I self-studied calculus, and took the AP Calculus AB exam. I was very surprised that I scored a 5 (the top mark), because at the time when I took the exam, I didn't know some very basic things that were on the syllabus.
The College Board gives the raw score to AP score conversions for the exams that have been most recently released. The percentages needed to get a 5 are as follows: