Ofsted should give a school a top grade on inspection only if it is found to be supporting other schools to improve, according to an education charity.
Challenge Partners has also called on the inspectorate to change the name of the top grade from "outstanding" to “leading school”.
The school improvement charity, which was formed to continue the successful collaborative approach used by the London Challenge, said schools should only be given the top Ofsted grade if they could show they shared expertise meaningfully with others.
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It was responding to Ofsted's consultation over its new framework, which closes this week.
Challenge Partners also calls on the inspectorate to recognise the value of peer reviews and questions the research base it has used in drawing up its new inspection framework.
Kate Chhatwal, the chief executive of Challenge Partners said: “Harnessing the capacity of the system is crucial if we are to achieve a truly self-improving, school-led system. As Ofsted aims to promote improvement, it should do more to recognise the impact of those schools and organisations that are active agents of school improvement.”
Challenge Partners said that if the inspection system is to drive school improvement, “it must more clearly incentivise the top performing schools to share their expertise with others.”
In evidence submitted to Ofsted’s consultation for its new inspection framework, Challenge Partners urges Ofsted to look for evidence that headteachers are “inviting challenge through peer review, looking outward, collaborating and sharing best practice to secure continuous improvement in their schools.”
The charity which works with more than 400 schools nationally also urged Ofsted to widen their research base and to ensure all inspections are led by fully trained and experienced HMIs or practitioners.
It said that inspectors should consider schools’ own evidence of progress, to ensure they can make nuanced judgments which are evidence-based and give schools greater assurance about their reliability.
Carolyn Morgan, the chief executive of Ascent Academies' Trust said: “The research overview used to develop the framework is entirely mainstream-based and includes no research base for those with SEND. In an inclusive education system, we would expect to see research used that reflect the whole system, as opposed to parts of the system.”
Dr Chhatwal called on Ofsted to acknowledge the benefit of peer review within schools.
She said: “School leaders are already working across the country on peer reviews and collaboration which together drive improvement in the performance of individual schools and the wider system.
“We have found that trusting teachers and school leaders to challenge themselves and each other, in an open process, works really well and enables them to share excellent practice and discuss issues freely.”
Over the last eight years, Challenge Partners has helped almost 2,000 peer reviews for individual schools and multi-academy trusts.