Fun with Excel: Average vs. Attainable II

I recently posted a spreadsheet that showed how only one in sixty-four students would graduate if the schools truly aimed for average. That spreadsheet was meant to be simple and easy to understand. Realistically speaking, the numbers I provided are highly favorable to the schools. I intend to add just a little bit more. The numbers will still be skewed favorably to the schools, but they will be very slightly less unrealistic.


One complication to my numbers could have been observed but misinterpreted. Generally speaking, students don't have grades vary widely between subjects. Subjects such as math and English are not tightly connected. The same could be said for physical education and art. What's causing good students to consistently meet expectations? In short, it's because the effort to achieve good grades exceeds the importance of ability in each individual subject. The schools aren't aiming for the average ability in each subject, they're aiming more towards attainable expectations along with decent abilities of being a student.

I'm still looking at the belief that schools aim expectations on the abilities of the average student. I will discuss attainability in the future. If the schools truly aimed for average, even the best students would fail about half the time. Similarly, bad students who have above average in potential would be likely to fail. This sort of failure relates to efficiency. My previous post relied on teaching being 100% efficient. In reality, our schools are highly inefficient. I will be way too nice again. I will revise my spreadsheet to reflect an unrealistic 90% efficiency rate.

There are other issues that also inflated my previous estimates. For example, I calculated based on median rather than average. The average ability should exceed the median. I also assumed that lessons within a subject would all be learned equally well. In reality, there would be some degree of fluctuation between individual lessons. Even at 100% efficiency, average students would be likely to fail. On top of all of that, I used the assumption that falling short of average was the lone cause of failure. While failing for reasons other than ability can occur at any ability level, I don't want to overcomplicate things. I have decided that these additional concerns can justify knocking off another 5% from my calculations. If I multiply abilities in each class by 85%, how many would still pass each required subject?

Once again, I have put together a spreadsheet to explain my views. This spreadsheet can be found at: Average vs. Attainable II.xlsx

The results are predictable. These changes have dropped the estimated graduation rate below 1%. This is still unrealistic. My 85% estimate is clearly high. There are also other considerations that could be made. For example, do students have to succeed at just six subjects throughout their schooling lives in order to graduate? The bottom line is that if the schools aimed for average as so many have claimed, graduation rates would drop below 1%. I think it's safe to say that we aim considerably lower.