Ofqual chair Roger Taylor has announced he will be stepping down from the role at the end of the calendar year after a "difficult summer".
He will be replaced by Ian Bauckham, who has been appointed as interim chair from January, pending the appointment of a chair for a fixed-term period "through fair and open competition".
Mr Taylor was first a member of the Ofqual board in 2012 before being appointed as chair in December 2016
He said: “Ofqual is an organisation of enormously dedicated and professional people who care deeply about the importance of qualifications and their role in supporting the benefits of high-quality education.
“After what has been a very difficult summer, I am leaving the organisation in good shape and in good hands. We have put in place measures for young people sitting exams in 2021 which represent the best approach to these difficult times.
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“I am delighted that Ian Bauckham CBE will be taking over as chair. Ian knows the organisation well, having been on the board since spring 2018. I look forward with confidence to its future success in ensuring there are excellent qualifications appropriate for the needs of all young people and learners.”
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Mr Bauckham said: “I was pleased to accept the role of interim chair of Ofqual and very much look forward to the year ahead as we continue our work to oversee examinations and qualifications across England.”
Mr Bauckham is the CEO of Tenax Schools Trust, a multi-academy trust, as well as the chair of Oak National Academy. He has been a member of the Ofqual board since March 2018 and a member of the Ofqual Standards Advisory Group since 2015.
In September, Mr Taylor said that, with hindsight, it was clear that the regulator’s grading algorithm could not overcome students’ feeling of unfairness over grades for exams they had not taken.
“The suggestion has been made that a different model might have led to a different outcome,” he told the Commons Education Select Committee.
"But the evidence from this summer, including from similar models implemented and withdrawn in Scotland, Wales and Northern Ireland, indicates a much more fundamental problem.
“With hindsight, it appears unlikely that we could ever have delivered this policy successfully.”
Education secretary Gavin Williamson said: “Following Roger Taylor’s decision to step down as Ofqual chair at the end of the year, I’d like to thank him for his contribution over the last eight years.
“Throughout this time, he has shown absolute commitment to ensuring qualifications are of the highest possible standard, while recognising the role they play in opening doors for both young people and adults.
“I am delighted that Ian Bauckham, who is already a member of the board, has agreed to act as interim chair until a substantive chair can be appointed. This will help see a smooth transition for work on exams and assessments in 2021 and beyond.”