Ofsted's incoming chief inspector has said that the watchdog's overall judgements on schools are not a "fair way" of assessing headteachers' performance.
Speaking today, Amanda Spielman said that this was because schools in poorer areas were less likely to get top inspection ratings because they were "harder to run".
She said that recent research suggesting schools with disadvantaged intakes are less likely to be rated “outstanding” than those with more privileged pupils, was in part probably a reflection of “reality, whether we like that or not”.
Earlier this week the Education Policy Institute published a report which found a “systematic negative correlation” between schools with more disadvantaged intakes and positive Ofsted judgements.
Speaking at an EPI event today, Ms Spielman – who is due to take over as chief inspector in the New Year – said that this was probably partly because it was more difficult to manage such schools.
"This draws attention to the fact that the grades would not be a reflection of the relative competence of the leadership teams," she said. "So the absolute school grades, would not be serving as a fair way to rank headteacher performance.”
Explaining her logic, Ms Spielman said: “It’s pretty widely agreed – I don’t think I’ve ever heard anybody say anything different – that a high disadvantaged school is harder to run.
“It follows that if you put staff teams of identical size and calibre into a high-disadvantaged and a low-disadvantaged school, and can magically keep other things constant, the absolute quality of education experienced by a given child will, on average, be higher in the low-disadvantaged school.
“If both schools were inspected, the reports – if inspection is done properly – would recognise this, and might, might result in a lower grade for the high disadvantaged school."
Ofsted and 'real life'
Ms Spielman noted that in “real life” things were not necessarily that simple, because of off-setting factors like pupil premium funding for more disadvantaged schools, although she said this was counterbalanced by the fact that it is “on average more difficult to recruit to high disadvantaged schools”.
However she went on to add: “At least part of the gradient the EPI has reported, which I don’t think is news to Ofsted or anyone else, probably reflects reality, whether we like that or not.”
Ms Spielman’s comments followed an earlier speech by Sir Michael Wilshaw at the same event, in which the outgoing chief inspector vociferously criticised the methodology behind the EPI’s report.
Sir Michael said that the “basic premise” of the thinktank’s research was “flawed” because it looked at judgments over a nine year period and therefore failed “to take account of important legislative changes and the numerous amendments by successive governments of attainment and progress”.
He said this approach masked the impact of his decision to shift Ofsted’s emphasis from pupil attainment to pupil progress, and the report therefore “did not compare like with like”.
Sir Michael said it was not Ofsted’s job to “artificially lower the bar” when inspecting schools with disadvantaged intakes.
As a former headteacher working in a deprived area, he said he would have felt “frankly insulted if I thought Ofsted was somehow going easy on the schools I led simply because many of the kids came from tough homes”.
During his speech, Sir Michael also defended the outspoken nature of his tenure as chief inspector.
“I have been accused of being abrasive and rather too forthright at times,” he said.
“I prefer to regard it as plain-speaking and telling it as I see it.”