I think this is a topic that has to come out of the various National, "Political", threads (isn't that indicative enough), & see the light of day.
Who honestly is surprised that:
- Teachers are shit at grading their own pupils (i.e. their own performance)
- Schools with wealthier families do better at State Exams
- Grade Inflation is still rampant
The irony in this is that the statistical model was probably bang on in the grade prediction; but the real problem for the Politicians, is that is showed clearly, the way that your postcode was the main determinant in whether or not your kid would get to go to University.