obtained a confidential copy of the guidance being used by inspectors for a pilot of the new regime. It said that schools obtaining a "satisfactory" rating for achievement - the minimum needed to avoid "likely" overall failure - could only have results below the national average if they were "improving steadily and therefore closing the gap with the national average for all pupils".
The finalised inspectors' guidance published today introduces a little more wriggle room by saying that schools do not have to be closing the gaps consistently. Otherwise, although the wording is different and even more lacking in clarity, it says the same thing. Despite this, Ofsted is still asserting that "special measures" or a "notice to improve", resulting in a probable P45 for the head, need not be inevitable for schools that fall foul of the condition.
The first point made by interim chief inspector Miriam Rosen this week was that schools would not be in the firing line for having below-average results. That would only happen if the gap with national averages was "statistically significant".
But many find any use at all of averages when judging schools to be infuriating. They point out that such conditions will always condemn a significant proportion of schools, no matter how much the whole system improves.
As Brian Lightman, general secretary of the Association of School and College Leaders, notes: "By definition, somebody has got to be below average."
However, Ms Rosen was unrepentant. "You could imagine a situation where the general level of attainment rises but we would still be failing schools," she said. "But if they were significantly below the average I think that would be reasonable."
She added: "Bear in mind that we are also looking at progress." And it is "progress" - a measure of pupils' achievement that takes into account where they started from - as opposed to the raw results of "attainment" that appears to offer hope to below-average schools.
It is the reason that Patrick Leeson, Ofsted's director of education, seemed to contradict the watchdog's own guidance when asked whether schools with below-average exam results that were not closing the gap could escape failure. "That will not be a reason to judge a school to be inadequate," he said. "If you are judged by inspectors to be not promoting or achieving good enough rates of enough progress for pupils whatever their starting point, the school will be judged to be inadequate."
That is a clear departure from the description of what a satisfactory school should look like set out in the official guidance for inspectors. The guidance on the grade for achievement contains no suggestion that good pupil "progress" can counteract a school failing to meet the conditions for attainment.
But that is exactly what Mr Leeson seems to be suggesting can happen in practice. He says the guidance is not a checklist and that final grades are always dependent on the professional judgment of inspectors.
The watchdog does seem to have managed to calm the fears of heads' leaders. "We don't expect schools to be judged purely on raw results," said Mr Lightman. "We have been reassured that Ofsted will be looking at the whole picture."
Ms Rosen has admitted that the new regime might lead to an increase in the number of schools going into special measures. But she also said the reaction to the pilot inspections from schools had been "overwhelmingly positive".
Heads of schools that have yet to face the new inspections will be desperately hoping that inspectors can use their own judgment. If they follow official guidance to the letter, the outlook for many schools in disadvantaged areas seems bleak.
Teaching quality gets pride of place in the new inspection framework
Ofsted is promising "an even greater focus" on teaching quality in its new inspections.
Education secretary Michael Gove expressed concern this month that schools were able to achieve overall outstanding inspection judgments without having outstanding teaching.
The watchdog goes some way towards addressing this point with new guidance for inspectors that says outstanding schools are "likely" to have achieved the same grade for teaching.
Teaching is one of four graded judgments - along with achievement, behaviour and safety, and leadership and management - that replace the previous 27.
Ofsted has also said that inspectors will spend "even more time" in the classroom - though it could not reveal how much more - and that they will hear primary pupils read.
Schools will be judged on how they fare with particular groups of pupils, including: boys; girls; ethnic minorities; lesbian, gay, bisexual or transgender pupils; Gypsy, Roma or Traveller pupils; the academically able; those with low-income backgrounds; disabled pupils; looked-after children; young carers; and other vulnerable groups.
There will no longer be separate graded judgments for the early years foundation stage or sixth-form. Schools will continue to receive around two days' notice of inspections.
Ups and downs
For four consecutive years Ofsted inspection results showed maintained schools getting better, with a steady increase in the percentage of outstanding schools and a steady fall in the proportion that were failed.
Then the inspectorate introduced a new framework for 200910, which focused more on the weaker schools and raised the expectations for all schools. The results saw the proportion of schools deemed outstanding nosedive and the percentage of schools that were failed doubled.
Ofsted is introducing another new framework in January. Are things about to get even tougher?
Original print headline: Wriggle room for `failing' schools as Ofsted says don't fret