Imagine if you could prove there was a problem so profound with GCSE English that none of the results was in any way reliable. None of them could be trusted.

Can you begin to imagine the outcry? The national outrage would be deafening. Questions would be asked in Parliament. A public inquiry, or somesuch, would be heard. Heads would roll. Wholesale reform would be undertaken. (Some of this happened in 2012, of course.)

Such a problem is pretty much what TES revealed last Friday: but it wasn’t GCSEs - it was in the key stage 2 Sats writing assessment. In response, there was little more than a murmur.

Helen Ward’s brilliant investigation found, if you’ll forgive a basic summary, that the moderation system for teacher assessment of KS2 writing was so flawed that it was, to all intents and purposes, obsolete. In fact, the findings confirmed a widely-held suspicion: that assessment of writing - in a post-levels system that demands “secure fit” rather than “best fit” - just doesn’t work.

Judging by results

Despite this, thousands of heads’ jobs will be dependent on these assessment results. Careers could be in tatters on the basis of a data set that looks a little less reliable than homeopathy. OK, so Ofsted and its ministerial masters might have indicated they won’t use the unreliable results to inform their judgements against schools, but there’s nothing to stop multi-academy trusts, local authorities and local newspaper league tables drawing dramatic, career-threatening conclusions.

And before anyone points out that the difference between GCSEs and Sats is that the former directly affects the life-chances of students, let’s remember that Sats scores stick to kids like muck. Pupils are told the results, are too often allowed to judge themselves by them, and most secondaries will, at the very least, use them to inform the next stage of their education. I wish it wasn’t so, but it is.

In short, these flawed results matter way more than they should.

It’s all well and good the government proposing to replace “secure fit” with a more relaxed regime based around “best fit” in 2018 and planning further tinkering with the technicalities of moderation, but all of this will be too late. Too late for 2017’s pupils and too late for too many headteacher careers.

Something - anything - must be done. It’s a national scandal. 

Ed Dorrell is head of content at Tes. He tweets @Ed_Dorrell

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