Ofsted has handpicked 23 schools to help it decide what good curriculum design looks like for its controversial new inspection framework.

The schools chosen were rated as good or outstanding and said to be particularly invested in curriculum design. The research will be crucial to how new school inspections focusing on the curriculum are developed.

Chris Jones, the inspectorate’s deputy director of research and evaluation said: “Our findings have allowed us to develop some more detailed indicators of high-quality curriculum design.

“The next phase of our research is to test these indicators to work out which ones are most useful for assessing curriculum intent, implementation and impact on inspections.”

However Ofsted has already faced criticism that its sample of schools favours a particular approach to the curriculum. Now Tes analysis reveals it is also unrepresentative in other ways:

• Seven of the 12 primary schools were academies - 58 per cent of the primaries in the study - compared with  27 per cent nationally.
• Of the 23 schools visited, free schools made up almost a third (30 per cent) compared with less than two per cent of free schools nationally.
• There is also a geographic imbalance. London and the East of England is over represented and the North West is significantly under represented.  
• The inspectorate did not include any schools for special educational needs or PRUs as part of this work
• Four of the schools out of 23 - a sixth of the study -  came from just two multi academy trusts: New Vision Trust and Inspiration.
• Of the 23 schools visited around a third were described by Ofsted as having a knowledge-led curriculum, half were said to be knowledge engaged and a small group were skills led. 

Ofsted has said that it identified strengths in all of the curriculum approaches it looked at and does not favour one over the other.

A spokesperson added: “We identified more schools as being in the knowledge-engaged category than at either end of the spectrum. Some in the knowledge-engaged group also placed a slightly greater emphasis on skills than knowledge.”

However critics of Ofsted’s plans such as Russell Hobby, chief executive of Teach First have suggested that the inspectorate cannot assess a school’s curriculum without having an pre-judged idea of what a good curriculum is.