One of Ofsted’s most senior officials has revealed that the inspectorate is just as reluctant to use this year’s writing assessments as it was in 2016.

The comments from Sean Harford, the watchdog’s national director of education, come as the government announced yesterday that it would look into changing the way writing is assessed for 2018.

Last year, Ofsted warned its inspectors not to base judgements of schools on the writing results.

Asked if inspectors would receive the same advice as last year, Mr Harford said: “Yes. Unless we’re convinced that there’s anything different this year than last year, then we will give the same advice that we gave inspectors last year…to treat it with caution.”

And it will remain “unless we are convinced that the frameworks have got better, that the moderation has got better… there isn’t evidence at the moment that that’s the case,” he added.

Last year’s confusion led the Department for Education to decide that schools that had dropped below the floor standard due to writing alone could not be issued with a warning notice unless the extent of change was beyond what could be explained by the reforms.

Russell Hobby, general secretary of the NAHT headteachers’ union, wants that guidance to stay. “We need to keep treating these results with caution until we have a stable system and we’re not there yet,” he said.

“The data should be reliable, but it isn’t. It should be a stark warning to us all. We need to get away from this idea that one number over one year can tell you anything meaningful.

“If, at the end of this, we can come out of this with that realisation, then that would be the silver lining in this cloud of assessment chaos.”

Harford was speaking earlier this month, following his appearance at the Primary Rocks conference in Manchester.

Details of just how much variation there was across the country in the treatment of writing assessments are provided by analysis from Michael Tidd, deputy head of Edgewood Primary in Hucknall.

The analysis of the writing results in primary schools shows many local authorities had far fewer children reaching the expected standard in schools that were moderated (by the authorities) than those that were not visited.

Tidd obtained the figures by using freedom of information requests to discover which schools were moderated. The results show that in 108 of the 138 authorities that replied, schools that were moderated had lower results on average than those that were not. And there was a large variation between local authorities in the gap between moderated and unmoderated schools.

He said that the variation demonstrated “the impossible circumstances” that local authorities face. “I think the biggest factor in the variations is that the whole charade was so open to interpretation and there was no clear direction on all of this from the centre,” he said.

“My personal view is that some of the local authorities that appear to have ‘lowered’ results were probably giving a fairer representation of what children are able to do independently.

“The guidance was so tardy and opaque last year that what we really learn from all this is not that any one local authority was better or worse at moderation than any other - merely that they were all trying to do a very difficult job in near impossible circumstances.”

A DfE spokesperson said: “The interim teacher assessment frameworks were designed, through discussion with curriculum experts and teachers, to produce reliable outcomes in place of the old levels system.

“The STA is continuing to evaluate the interim teacher assessment frameworks, including listening to feedback from the profession.”

This is an edited version of articles in the 31 March edition of TES. Subscribers can view the full articles here and here. This week’s TES magazine is available at all good newsagents. To download the digital edition, Android users can click here and iOS users can click here