Ofsted will use schools’ test and exam performance data from 2019 in its future inspections - but has admitted this approach has its limitations.

Chris Jones, the watchdog’s director of corporate strategy, said that inspectors will have to use 2019 results because of the disruption to the exam series caused by the Covid pandemic in 2020 and 2021.

Headteachers have called for clarity on whether the watchdog will weight the results differently, given that they are two years’ old.

Ofsted: How Covid has changed inspections

Inspections: Ofsted set to return to full programme in September

School judgements: Return of full Ofsted inspection was delayed twice

The inspectorate looks at performance data as part of its judgement on the quality of education that a school provides.

However, under its education inspection framework (EIF) launched in 2019, it gives less weight to exam results and places more focus on the curriculum than in previous inspections regimes.

Ofsted school inspections will use 2019 exam performance data

In an article published today looking at feedback from schools about the education inspection framework, Mr Jones said: “A small number of the leaders and staff that we spoke to in our focus groups, though, felt that the pendulum had swung too far away from considering attainment.

“There was a perception among some of these that Ofsted no longer considers pupils’ attainment at all. This is not the case: inspectors still use published national performance data as a starting point in inspection, and pupils’ performance in national tests and examinations is included in one of the grade descriptors for the quality of education.

“But national tests and examinations are only one indicator of the quality of the curriculum, so we will continue to use published attainment information in a balanced way, alongside all the other valuable information we gather during inspections.

“Because of the disruption to the 2020 and 2021 exam series, we will have to use published data from 2019 in future inspections, recognising all its limitations.”

Geoff Barton, general secretary of the Association of School and College Leaders, said: “Schools are going to feel aggrieved if they believe they have been on an improving trajectory since 2019, but, of course, it would also be problematic to attempt to use 2020 or 2021‘s results.

“I think we need clarity on how much weight Ofsted will be giving to the 2019 performance data.”

The new EIF framework was used by Ofsted for less than two terms before the coronavirus crisis led to inspections being put on hold in March 2020.

Routine inspections are set to resume in September.

Last month the watchdog said that teacher-assessed grades would not be used to measure the impact of the school curriculum, as it outlined how it was altering inspections to take account of the Covid crisis.