Schools are being downgraded by Ofsted if children questioned by inspectors cannot recall the names of rivers in geography or struggle to explain key concepts in history, according to headteachers.

Under a new inspection framework, schools risk being marked down if pupils fail to adequately recall or articulate what they have been taught, sometimes years before, when given an impromptu “pop quiz” by inspectors. At one flagship secondary school, an outstanding rating was lowered to good when 11- and 12-year-olds were unable to explain clearly “the principle of the rule of law”.

Ofsted inspections in England were resumed at the end of last year after a suspension during the pandemic. Schools are being judged under a new framework introduced in 2019, which focuses more on teaching and the curriculum. Outstanding schools that were, up until recently, exempt from routine inspection are now being visited.

Amanda Spielman, Ofsted’s chief inspector of education, has said that she expects the number of outstanding schools, currently one in five, to be cut by half under the new regime.

As part of the framework, inspectors conduct “deep dives” in four to six subjects to explore planning, teaching and the impact on pupils’ learning. This involves inspectors asking randomly chosen pupils about what they have learned to test what they know and have retained.

Headteacher organisations are increasingly concerned that schools are being marked down on the strength of the responses given by nervous children, some of them infants, questioned without prior warning by adults they do not know.

Inspection reports refer to “gaps in pupils’ knowledge and understanding” and cite instances of pupils not able to remember or articulate taught content or who display “shallow” or “disjointed” understanding. Schools say too much weight is being given to these responses. The Ofsted handbook says inspectors must take “a rounded view” of the quality of education and use a variety of types of evidence in their judgments.

Despite having the best GCSE results in its borough in 2019, and achieving outcomes for disadvantaged pupils that are higher than the national average for non-disadvantaged students, Ursuline High School, a Catholic girls school in Wimbledon, has just been demoted from outstanding to good.

The school, deemed a flagship secondary by Merton council, has challenged the judgment. It believes the downgrade is due, in large part, to the lead inspector’s concern about responses by Year 8 pupils to questions he posed about “the principle of the rule of law” which they had covered in Year 7. According to the school, this incident has been given too much significance and wrongly used as evidence of a more systemic issue in the quality of education. In the 2019 GCSE results, 85% of history students at the school were awarded grades 9-5, with half achieving the top grades of 7-9.

Ursuline High’s submission to Ofsted said: “The school does not dispute the finding that the topic of the rule of law was not sufficiently explicit in the schemes of learning. The school is, however, disputing the disproportionate weight placed upon that fact to support the overall assessment that its quality of education is not therefore outstanding.

“That would be to place an undue … weight on that one piece of evidence and inconsistent with the overarching thesis that an accurate judgment on quality must be reached only after taking all evidence into account.”

In another instance, inspectors who downgraded Coalway Community Infant School, in the Forest of Dean, from “outstanding” to “requires improvement”, cited an instance where pupils, who are aged up to seven, could not “order important events in history as they have gaps in their knowledge”.

Headteacher organisations said last night that other schools have had similar experiences.

“School leaders are increasingly worried about the conclusions some inspectors draw in response to pupils saying the ‘wrong’ thing or giving the ‘wrong’ answer or not understanding a question,” said Ian Hartwright, senior policy adviser at the National Association of Head Teachers. “It is really problematic to try to gauge how much children know by asking them ‘pop quiz’ questions and seeing if they remember things and can articulate [them] adequately. This kind of approach is subjective and variable. Neither of these is a good thing in an inspection system where you need consistency.”

He cited an example of a school that felt it had been marked down because pupils in a geography class could not remember the name of a river they had covered in a lesson.

“I’ve just had another example come across my desk last week where a school is absolutely convinced that they meet the criteria for outstanding but they were tripped up because children were asked about something they learnt in a previous year in design technology and they weren’t able to remember. According to the inspector, that showed that their knowledge wasn’t consolidated,” Hartwright added. “But there simply isn’t time for inspectors to accurately interrogate the curriculum in this way in a two-day inspection.

An Ofsted spokeswoman said: “Talking to pupils is an important part of the inspection process, to help assess whether the school’s intentions around teaching are matched by what pupils actually know and understand. But it is never the case that pupils’ answers to questions would be the sole reason for a change in a school’s grade.”