I think thismwill have to be a big statistical exercise, based largely on prior attainment of students and schools, with pretty limited input and impact from schools.
Schools have a wide range of evidence which isn't comparable. They set mocks differently and record attainment differently, so askimg for specific types of info won't work as its not comparable. Probably schools won't be asked for evidence as it isn't comparable, nor a breakdown of statistics, but just one overall expected final grade given a variety of pieces of info a school might want to bear in mind depending on which they actually have. This will be an expected grade a candidate would have achieved innthensummer exams....not the same as the level they are working at now.
Ofqual will feed this info into their formula, but probably more important will be students' prior attainment at GCSE and school prior attainment at A Level over several years.
In the end Ofqal need similar proportions to get similar grades in each subject to previous years. To do this they will have to project forward. Perhaps schools will be asked to rank students in each subject. Then if for example, a school usually gets 30% A in maths, they will factor in their prior attainment at GCSE, the teacher predicted grades and award 35% of student (to be on the safe side) an A at that school.
This really will be the only fair way in this situation, given making comparisons and considering individual pieces of evidence just won't be viable. The outcome will be that students with excellent GCSEs in schools which historically get excellent A Levels, will get excellent grades this summer. This would happen if they sat the exams and it will still happen under this system. In less highly performing schools, some students will get top grades, but less than in the previously mentioned schools....as is always the case. For most students the outcomes will be fair. And this is key, it has to be fair for most students. Some students might feel disadvantaged - they might say they didn't do so well at GCSE but we're going to do brilliantly at A Level. Of course we will never know as they won't sit the exam, but in reality, few do brilliantly as A Level after poor GCSEs. Ofqal might be able to incorporate something into their formula for disadvantaged students because actually there is evidence that they often do underperform at GCSE - this would probably rely on some info from schools abiut individuals.
Schools that over estimate the grades for their students won't actually get higher grades - because student prior attainment at GCSE and the school prior attainment will be huge factors in determining outcomes.
Some students will be disappointed. That is always the case when people take exams too. In this scenario where they feel the outcomes are unfair, the chance to appeal is likely to be a chance to sit the exam in the autumn whenever that might be. It is unlikely to be based on providing evidence as again, it is just impossible to gather comparable evidence. Only an exam could be used as a genuine challenge. Most won't want to sit an exam in the autumn but the option will be open to all.
This is what I think must happen just based on the practical realities of it all. Work students do now won't alter the grade their teacher gives them. Most will get grades which do fairly reflect what they would have been highly likely to achieve....although whether they feel that is what they were likely to achieve isn't always the case - lots of students believe they will do better thanntheybactually do every year. If they feel it's really been unfair or they can do better, they can do the exam. I suspect numbers doing this wil be small but I might be wrong. To do these exams they would have to study and that will be hard at that point, but does give them a genuine chance to prove themselves.
Let's see what happens.....but the more I think about it, the more I think schools won't be asked to submit actual work or break-down their expected grade into lots of little bits of evidence/justification, as those things aren't comparable or practical given the situation.
I think it's out of the student's hands now. No school will want their students to do badly.
If a student's A level target is a B, but they got a C for AS and Cs/Ds all year, then well there's no way I'm predicting them a B, no matter how much last minute cramming they reckon they would have done!