> My anecdotal experience from teaching math in higher ed for 20 years is that the variation in initial performance might be due to passing students who don’t d

> My anecdotal experience from teaching math in higher ed for 20 years is that the variation in initial performance might be due to passing students who don’t deserve to pass. This still does not explain why some performed less than others (the ones that should and ones who should not pass). > I have no expertise on this topic but it seems to me that some people are truly smarter than others. This is a fact indeed, but the real question is how much variability in performance/learning this explains, and if there are other factors that explain part (and how much) of this variability. For this we need data.