Schools could see their Ofsted grades suffer if inspectors find that their data collection systems are creating "unsustainable" teacher workload, Amanda Spielman has warned. 

The chief inspector also told today’s summer conference of the National Governance Association that Ofsted does not want to see school-generated data about the gap between disadvantaged pupils and peers in the same school.

"Internal data that your school uses certainly shouldn’t be collected in a way that puts undue pressure on teachers’ time," Ms Spielman said. "If someone shows you a great big spreadsheet, you might want to ask who pulled it together and for what purpose.

"Who does the data help? Does it add value beyond what you’d get from talking to a teacher or head of department? Was it worth the time taken out of the teacher’s day to enter all those numbers?"

In her speech, she noted that the DfE’s teacher workload advisory group’s report Making Data Work recommends no more than two or three data collection points a year.

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She told the governors: “If your school is using more than those two or three points every year, they should be very clear about how they will be interpreting that data and what actions will be flowing from it.

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“And if we find that a school is running data collection systems that seem disproportionate or inefficient or unsustainable for staff, we will endeavour to reflect this in our inspection reports and it could affect the grade that is given, but we are certainly not prohibiting the use of data.”

In a published draft of her speech, the chief inspector went further, saying Ofsted "could well grade the school less than good". 

On the pupil premium, Ms Spielman said: “We won’t be asking for any specific document or plan, other than looking at your school’s pupil premium strategy.

“And we certainly won’t need any further school generated data about individual students or closing gaps within classes or within the school. The data just isn’t particularly helpful here because the numbers of pupils are usually too small.”

She told the conference that Ofsted will be looking at the rationale for how the pupil premium funding is spent and what impact the school wants it to have.

However, she added that “all we are doing is making sure that you do what the DfE is telling you to do”.

The chief inspector also said that the efforts of schools to maintain standards have prevented the impact of funding pressures being reflected in Ofsted judgements.

She acknowledged governors’ concerns about school funding, and the “difficult choices” this had led school leaders to make.

She added: “The fact that we haven’t seen the effects flow through into inspection outcomes, or not yet, reflects the efforts your schools have put in to maintain standards of education.

“And, of course, I am aware of the wider context of cuts to local authority children’s services.”

Ms Spielman was asked how secondary school Ofsted ratings would be affected by the proportion of their pupils taking the EBacc combination of subjects.

She noted that there was a national policy for 90 per cent of pupils to eventually take the EBacc subjects, but that “it is not translated into expectations for individual schools”.

She added: “We have made clear in the handbook that we will be looking at progress in that direction but we absolutely are not looking for schools to hit a particular number.”