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of many shocking things I& #39;ve read about the A level cluster, this is, I think, the worst. https://ffteducationdatalab.org.uk/2020/08/a-level-results-2020-how-have-grades-been-calculated/">https://ffteducationdatalab.org.uk/2020/08/a...
if your Maths A level class is predicted .2% A*s, 95% As, 4.6% Bs and .2% Us, and you have a class of 20, guess what the grade breakdown is
Maybe it& #39;d be 19 As and a B. That& #39;s the least error, right? But it deprives that top student of their A*. So maybe it& #39;s A*, 18 As and a B. But that gives a student an A* for the same probability that no-one gets a U. So maybe it& #39;s A*, 17 As, a B, and a U? But that& #39;s too few As.
No: the actual ranking for that class would be 19 As and a U.
Even better: that class could be predicted 0.2% Us *even if no-one in previous years had ever been given a U*.
Here is a real school& #39;s data from the linked article:
Past years: 12.5% A* (…) 0% U.
Expected grades after "prior attainment adjustment": 5.71% A*, 2.3% U
Actual marks given to a class of 27, where each pupil is 3.7% of the total: one A* and one U
Past years: 12.5% A* (…) 0% U.
Expected grades after "prior attainment adjustment": 5.71% A*, 2.3% U
Actual marks given to a class of 27, where each pupil is 3.7% of the total: one A* and one U
Your class can be predicted a U even if no previous class has ever got a U. And once your class is predicted a U, someone has to be given it, even if the proportion of the class expected to get a U is less than one student.
WHERE INDEED https://twitter.com/dsquareddigest/status/1294202164248813573?s=20">https://twitter.com/dsquaredd...
love the understatement
