Ok, I'm stepping in on this thread as one of the few people in the room when the predicted grades were created by the teachers.
First up, for many A-Levels a significant portion of the course had already been marked and externally assessed. So, in the case of a practical subject (e.g. Art, Dance, etc) or a coursework based one (like History), that was somewhere in the region of 60% of the grade standardized by OFQUAL. Therefore, teachers were required to just predict the final 40% - which was based primarily on mock exams, which students often do worse at.
In the case of all Sixth Form Colleges (arguably the leaders in the sector) we based our predictions on three years of LV3A data (which is the most accurate data set available). Any grades we awarded were within that margin. Ironically the OFQUAL algorithm completely ignored historical data as it should have been modelled.
Sixth Form Colleges, as a sector had their grades go down, with many Colleges reporting their lowest results in 15 years. These figures were masked by the huge increase in grades in the private sector. It turns out the algorithm was not designed to cover small classes, so private schools (with their small classes) were given their inaccurate teacher predictions instead. Meanwhile the state sector was forced to follow the algorithm and was downgraded to offset the private school increases.
It gets worse….
In the Sixth Form Colleges were found the Government’s algorithm was taking the top 5% of students and inflating their grades – well above the teacher predictions. BUT taking the bottom 25% of students and substantially lowering their grades. The overall percentages of A-B looked normal, but when you drilled down, we discovered that students from poorer/disadvantaged backgrounds were basically being robbed of their grades. The whole algorithm was creating a fake top tier.
The most accurate predictor of A-level results was always AS levels, but the private sector campaigned to have them removed, as it made it harder for them to game the system.
Closer to home, our State Sixth Form College, out-performs the private sector every year - except this one. Our students normally have a 7% higher chance of graduating with a first class honours than any private school.
This was either incompetence by OFQUAL or gerrymandering.
