The first rule of progress measures is: they can’t be predicted. The second rule of progress measures is: there is no such thing as expected progress.

Ofsted gets this. In March, it stated: “Ofsted does not expect any prediction by schools of a progress score, as they are aware that this information will not be possible to produce due to the way progress measures at both KS2 and KS4 are calculated…‘Expected progress’ was a DfE accountability measure until 2015. Inspectors must not use this term when referring to progress for 2016 or current pupils.”

This is hugely significant because it recognises that levels, along with their built-in progress pathways, are truly gone. Progress is no longer prescribed in advance; instead, each pupil’s attainment is compared against the average score of pupils in the same prior-attainment group nationally.

To calculate progress in advance, schools would need to be able to predict the following:

* Any changes to DfE methodology.

* Each pupil’s key stage 2 scaled scores.

* The national average scores for each of the prior-attainment groups.

‘No one can define what it is they are asking for’

This, of course, is impossible, but questions such as “what percentage of pupils are on track to make expected progress?” are common, both in conversations between senior leaders and teachers, and in forms sent out by various external agencies. The data is expected, but no one can define what it is they are asking for.

It is not surprising that this desire to measure progress has resulted in the reinvention of levels in 101 different ways. Many, if not most, tracking systems offer a series of best-fit steps with associated numerical values and an expected rate of progress of anywhere between three and nine points per year. Progress in these systems is still focused on coverage and is still seen as linear. Such measures are contrary to the principles of a curriculum that prioritises depth and breadth of understanding, and can even be a threat to learning if they promote pace at the expense of depth.

Schools want to measure progress and I understand that, but we need to stop using teacher assessment for anything other than formative purposes.

To introduce elements of accountability into the process risks compromising the overall reliability of assessment and is counterproductive; we need to recognise that it is impossible to measure progress with teacher assessment without reinventing levels.

In short, if you really want to measure progress, use standardised tests.

James Pembroke founded Sig+, a school data consultancy, after 10 years working with the Learning and Skills Council and local authorities www.sigplus.co.uk