An Ofqual adviser has warned that exam boards will have difficulty restraining "wildly inflated" teacher-assessed GCSE and A-level grades this year, resulting in "Weimar Republic levels" of inflation.
Barnaby Lenon, a member of the Ofqual Standards Advisory Group, told Tes that the proposals for awarding grades this year do not measure students to an agreed standard or rank them fairly.
And he has predicted that higher grades will lead to high numbers of students dropping out when they reach the next level of education.
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An Ofqual and Department for Education consultation on arrangements for awarding GCSE and A-level results this year – following the cancellation of exams because of the coronavirus crisis – closes on Friday.
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It has proposed that GCSE and A-level grades are awarded through teacher assessment, with students sitting external tasks set by exam boards as part of the evidence teachers will use to assign grades.
In a letter to education secretary Gavin Williamson earlier this month, Ofqual's chief regulator, Simon Lebus, warned that grades would be less reliable as exams were not going ahead, but he has also said that grading in 2021 will be in line with that of 2020.
Mr Lenon said: "In any qualifications system you normally have to do one of two things. You have to either measure a pupil’s knowledge and grade it against an agreed standard or you have to rank pupils fairly in some way and then assign them grades.
"The current proposals do neither of these things.
"There will be no obvious attempt to limit the number of grades awarded at each level – a fundamental requirement for most qualifications systems," he added.
"The question is – does it matter if we have Weimar Republic levels of inflation this year? It could mean that plenty of students will get to university who should not be there and many GCSE pupils will embark on A-level courses only to drop out or fail.
"A fundamental question is: can exam boards push back against wildly inflated teacher grades? The answer is: with difficulty. They have a limited number of examiners and 6.5 million grades to check, each awarded on a different basis."
Ofqual has been contacted for comment.