Almost 40% of A-level results have been downgraded after exams were cancelled due to coronavirus.
In England, 35.6% of marks were adjusted down by one grade, 3.3% were brought down by two, and 0.2% came down by three.
Overall, an estimated 280,000 entries have been affected by the process.
This is because the Joint Council for Qualifications “standardised” schools’ predictions using historical data to try and maintain consistency in a year thrown into chaos by the pandemic.
Teachers were told to submit the grades they thought each student would have received if they had sat the papers, alongside a rank order of students, after exams were cancelled due to COVID-19.
Exams watchdog Ofqual says standards across the country have been maintained, with top A* and A grades rising by 2.4% to an all time high.
The number of students accepted on to degree courses has also risen by 2.9% compared with last year.
The UK government has announced it will not be scrapping the moderated results, like political leaders in Scotland were forced to do after criticism students from deprived backgrounds were hit harder by the algorithm.
But it says there will be three routes of appeal.
Students can use their mock exam results to argue they should have got higher grades, a school can say it is under new leadership meaning it should not be judged on old performance and some pupils can press ahead and do the actual exams in September.
Education Secretary Gavin Williamson said he wanted to “make sure young people have the best possible options in front of them” despite the coronavirus outbreak.
But there were several reports of disappointment, one person tweeting: “My sister got her A-level results today! Her mock results were A,A,A – her centre assessed results were A*,A,A* which she 100% deserves. Yet because of clever Boris’ algorithm she’s ended up with B,B,C … HOW do you come to that result when NONE of her work has ever been graded that?”
Geoff Barton, head of the Association of School and College Leaders, said he had heard “heartbreaking feedback” from teachers about “grades being pulled down in a way that they feel to be utterly unfair and unfathomable”.
Labour’s shadow education secretary Kate Green also branded the government’s approach to exams as “chaotic”.
“Today is always an anxious day for pupils and parents across the country,” she said. “That anxiety is far worse this year because of the fiasco caused by the Conservative government.”
And the children’s commissioner for England Anne Longfield also said “inequalities already existing in the education system will be deepened”.
She warned “more affluent schools with more resources are more likely to appeal” so the process should be “as easy as possible” to ensure “disadvantaged schools and students are not left out”.
In Wales, where students take AS-Levels which count towards their final A-Level, pupils have been promised they will not get a lower final result than their grade last summer.
Analysis: The system was never going to be perfect
By Laura Bundock, news correspondent
This is no ordinary results day.
An exceptional situation, involving difficult and delicate decisions ever since exams were cancelled back on 18 March.
We now know 35% of results have been downgraded by one grade. Some results by more than one grade.
Ofqual insists its analysis of grading shows no negative bias on socioeconomic background, gender or ethnicity.
A general system assessing thousands of individual pupils was never going to be perfect.
But already unions say they’ve received “heart-breaking” feedback of schools feeling unfairly and unfathomable downgraded.
And for students caught in the middle, they must hope universities and colleges follow through on their promise to be flexible with admissions.
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