Ian Bauckham, interim chair of the exams regulator, told heads it would be “wrong and fundamentally unfair” if judgments were subject to pressure or interference by people “with a vested interest”.
His comments came after the Government confirmed last month that teachers in England will decide pupils’ A-level and GCSE grades this summer after exams were cancelled for the second year in a row.
Mr Bauckham said: “We have said as a principle of transparency that candidates should know on what evidence their grade has been determined.
“However let me be crystal clear about the following point. That principle – which we believe is right and appropriate in the context of this year’s approach to grading – does not mean that either the selection of evidence, or the decision about the grade which the evidence supports are somehow topics for negotiation between teacher and student, or teacher and parents. They are not.”
His comments came after Richard Sheriff, president of the ASCL, warned parents with “pointy elbows and lawyer friends” could widen the equality gap if they apply pressure to teachers deciding grades.
Mr Bauckham told heads: “It would be quite wrong and fundamentally unfair both for teachers and students for these decisions to be subject to pressure, or interference from those with a vested interest.
“That would risk discrediting the process and ultimately could end up with young people in destinations for which they were ill-prepared, potentially displacing those better suited to them.”
Education Secretary Gavin Williamson has insisted that grades decided by teachers will be fair amid concerns that the plan will result in grade inflation.
But addressing school leaders, Mr Bauckham said he expected some teachers, who would be acting in good faith, to award grades above that which every student would achieve if exams had gone ahead this summer.
The interim Ofqual chair suggested that teacher judgments “inevitably” will have an impact across the system.
Mr Bauckham said he did not believe this would make qualifications less valuable this year, but he said it would not be “sustainable” in the long-term.
Addressing delegates at the union’s virtual conference, the Ofqual chair said: “Over time, if repeated year-on-year, it would of course cumulatively erode the value of the qualification.
“So it will need to be controlled, but to do so we will need to be at the point where we can again offer fully regulated national examinations and this year we quite simply cannot.”
Speaking to headteachers, Mr Bauckham explained how more GCSE pupils could receive the top grades this summer after exams have been cancelled.
In a speech, he said: “Imagine I am a pretty self-disciplined teacher determined to act with integrity in grading my students.
“In 2021, I have a class of 30 Year 11 GCSE candidates and five of those candidates have produced work on more than one occasion, and under reasonably controlled circumstances, which leads me to believe that they are capable of getting a grade nine on the day of the exam.
“In reality I know, because I’ve been at this for a while, that all five probably won’t quite manage it on the day despite the evidence. The problem for me is I can’t be sure which of the five will and which won’t.
“So acting with complete professional integrity, using the knowledge I have of normal grading standards, the range of evidence I have of those students’ performance, following exam board guidance, I decide to submit a grade nine for all five of them.
“That small act of professional judgment – made in perfectly good conscience with good evidence available for scrutiny if requested – inevitably will have an impact when it’s repeated across the system.”
On Wednesday, Ofqual confirmed that A-level and GCSE students would be able to see optional assessment questions – which teachers can use to help decide pupils’ grades – in advance.
The move prompted criticism from education leaders who warned that making materials publicly available could benefit more privileged students.
Mr Bauckham said that trying to keep a set of questions confidential would “inevitably” result in the exam board material being leaked, which could disadvantage pupils who sat papers in secure conditions earlier on.
He added: “At the end of the day, there’s going to be quite a lot of tasks and questions and if you take the average GCSE student who might be doing eight, 10, 12 GCSEs they are going to have to prep and memorise a vast amount of material if they are going to do it in all the subjects they’re taking.
“And actually perhaps if they did that, it might be a rather good learning experience for them anyway.”