Children who choose to sit A-level and GCSE exams this autumn will be treated with "generosity" by markers, Ofqual has admitted.
Pupils in England who were unhappy with the grades they received this summer, or who were unable to receive a grade at all, can enter for A-level exams later this month and GCSEs next month.
But in order to make it fair, the exam regulator said it will "carry forward the generosity" from grades that were handed out this summer based on teachers' predictions.
In a normal year, exam grades would be standardised using statistical predictions to ensure that roughly the same proportion of pupils achieve top grades from one year to the next.
But Ofqual said this approach would be of "limited usefulness" for the autumn exams due to the low numbers of students taking them. There are just over 20,000 entries for A-level exams this autumn, out of a possible 700,000.
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The regulator warned that students that even though this is not a "typical" re-sit exam, they should not assume they will improve their grades by taking exams this autumn.
"Not all students in the autumn will have been able to receive a grade in the summer, but of those that did, many will be hoping to improve their grade from summer 2020," Cath Jadhav, Ofqual's associate director of standards and comparability said.
"However, it is worth noting that, in previous years, many re-sitting students do not improve their grades."
It comes after the fiasco around grading of GCSE and A-level students this summer, when exams were cancelled amid Covid-19.
Thousands of A-level students had their results downgraded from school estimates by an algorithm, before Ofqual announced a U-turn, allowing them to use teachers' predictions.
In a blog on the watchdog's website about the autumn exam series, Ofqual said exam boards will "rely much more heavily on the judgment of their expert senior examiners" due to lower entry numbers.
In the summer, the proportion of GCSE and A-level entries in England awarded top grades surged to a record high following the grading U-turn.
Last week, Education Secretary Gavin Williamson announced that the 2021 exams will go ahead in England, but they will be delayed by three weeks next year.
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