The drip-feed of information on the 2019 framework continues. On the back of HMCI’s announcement of the new four inspection judgements comes further detail of the next level down, in the form of an online slideshow. So, what are we to make of it all?

For a start, you would be hard pressed to put your finger quickly on what lines of enquiry have been removed. The 2019 framework is being billed as “evolution, not revolution” but, on the face of it, the scope of what is inspected is growing not diminishing.

Current plans (titled “Judgements - our working hypothesis”) suggest that most sub-judgements have been retained, albeit moved around (pupil outcomes and teaching and learning are still there) with further sub-judgements added - most notably curriculum design and delivery, workload and off-rolling.

All important issues - no argument there - but if we are to add, do we not also need to take away?

Through the NAHT heads’ union’s recent Commission on School Accountability, we heard from Ofsted inspectors who described inspection under the current framework as “an impossible task”. The 2019 framework, on the face of it, looks no more workable.

What can be achieved in a limited time?

The much-heralded shift of focus away from results themselves on to how schools achieve their results does not necessarily save time on inspection. In fact, I suspect that it might end up being more time-consuming to do well.

Which begs the question, how on earth will inspectors do this justice, in the very limited time they have on site?

In the past, Ofsted might well have expected schools to have done some of the heavy lifting in advance by having information ready for inspectors to consider. Not now, as Ofsted has been at pains to emphasise that inspection will not drive unnecessary workload. In fact, senior Ofsted officials have gone further and said that the new framework will actually reduce workload on schools preparing for inspection.

Might inspection get longer to accommodate the new requirements? It would be an odd contradiction for the weight of scrutiny to increase as the number of “good” and “outstanding” schools continues to rise. It is also unlikely that the government will find more money to pay for longer inspection in the current financial climate, while expecting more from inspectors is unlikely to land well with an inspection workforce that already considers itself overworked and underpaid.

The issue for Ofsted to resolve is how to successfully raise expectations of “better” inspection while reducing (or at least not increasing) the associated workload for schools.

The answer must surely lie in prioritising what we really want and need Ofsted to scrutinise. It cannot do everything. If inspectors spread themselves too thin, then they risk doing everything badly. Let us be honest and realistic about what can be feasibly expected of the inspectorate with the resources at its disposal.

The “working hypothesis” wish list needs to be whittled down to an absolute must-have list.

How can Ofsted make the greatest difference?

The accountability commission concluded that Ofsted should focus its resources and inspectors where they can make the greatest difference - identifying failure and providing a deep diagnostic insight to schools that are struggling in order to help them to improve.

All other schools, the vast majority that are neither failing nor struggling, should expect very little from inspection, other than a short check to ensure that good standards are being maintained and that the education of their pupils is in safe hands.

If there is too much to review, inspection becomes too cursory. With limited time on site and when faced with so many areas to judge, it is hard to see how inspectors will be able to make reliable, consistent judgements.

Last week I spoke to a secondary headteacher of a school with 1,600 pupils, who commented that their most recent inspection lasted one day with just two inspectors. This was a “good” school, but it is hard to believe that inspectors were able to give anything other than a cursory glance at most aspects of the framework in that time. More likely, the data looked right and a quick “sniff of the air” on site suggested that this remained a “good” school.

Our hope for a new framework must be that we don’t replace one game with another. Over the past few years, the game has favoured the data-literate, the data-savvy. In reducing the emphasis on data and increasing the attention paid to curriculum, we must ensure that the “winners” will not simply be those who can articulate a story of curriculum excellence with the most convincing rhetorical flair.

Nick Brook is deputy general secretary of the NAHT headteachers’ union, and chair of NAHT’s accountability commission