A couple of academics have, with a single devastating insight, blown a sizeable hole in our national preoccupation with school league tables. Parents who waited eagerly to pounce on the latest set of figures when they were published by the Department for Education on Thursday should read on before wasting too much time assiduously fine-combing the data on the schools in their area.
The researchers at Bristol University began with this simple thought. Suppose you are choosing a school for your child from next September. The exam results which should really concern you are not this year's but the ones which will come in 2018 when your little darling sits whatever configuration of testing the Education Secretary Michael Gove leaves behind when he returns to the backbenches after the next election. But the results which came out on Thursday show how kids did in 2012. So that means there is a seven-year gap between the available information and what parents really want to know.
What the social statisticians Dr George Leckie and Professor Harvey Goldstein have done is turn the issue upside-down. They used data from seven years ago to predict how today's schools ought to have done - and compared that with how they actually did. They found many schools moved, in just seven years, from the top quarter of results to the bottom. Worse still, they found the seven-year predictions were "so imprecise that almost no schools could be distinguished reliably from one another". A blindfold and a pin would be just as effective.
Yet prediction is woven into the British education system. Cambridge University recently attacked Mr Gove's plan to alter the A-level system and scrap the intermediate AS-level exams taken by sixth formers at the end of their first year. AS-level results provide crucial data for identifying the most talented applicants, Cambridge's research has found; they are far more reliable than old-style A-level predictions by teachers.
Ending interim AS-levels will make life more difficult for university admissions tutors. But it will also discourage weaker students from embarking on A-levels in the first place. And it will disadvantage poorer kids because it will increase universities' reliance on interviews and written statements in which middle-class kids have parents and teachers to coach them.
The Gove plans, of course, propose much more. He also wants to replace the GCSEs taken by 16-year-olds with an English Baccalaureate in English, maths, two sciences, history or geography and a foreign language. And by 2015 he wants A-levels to stop examining by topic modules over two years and instead have just one big exam at the end.
The opposition to the Gove reforms is formidable. The universities are unhappy. Business is unconvinced; the employers' organisation the CBI wants more rigorous exams but says the Gove plans lack coherence. Teachers' unions say that changing A-levels and GCSEs at the same time will put intolerable pressure on schools. Educationalists, head teachers, exam boards and even the exam regulator have expressed major doubts. So have activists in the arts, theatre, design, computing and engineering.
Dr Christopher Ray, High Master of Manchester Grammar School, who chairs the independent schools' organisation, was last week withering when he wrote to parents: "The various components are rushed and incoherent. This does not betoken respect for the young people whose education will be reshaped by a process jumbling together changes to GSCE and A-level, while leaving inadequate supervision of examining unreformed - and all to a timetable based on electoral politics rather than principles of sound implementation." Ouch.
Even the academic whose work on GCSE grade inflation Mr Gove cited in announcing the EBacc appears bewildered. "I don't know what they are thinking or who they have talked to," Robert Coe, professor of education at Durham University, has said. "Where are the models for this?"
Michael Gove will probably just take all as proof that he is right. After all this is the man who, in opposition, wrote: "The real enemy of excellence is the entrenched, complacent, educational establishment". Which is why, no doubt, Mr Gove bypassed establishments of all kinds by cooking up his plans from a private email address which he hoped was not subject to scrutiny under the Freedom of Information Act.
The irony is that Mr Gove's instincts, in many ways, are correct. He rightly bemoans a past tendency to "too much assessment, too little learning". And he wants to encourage a deeper understanding of subjects. But will his changes bring that about? There is no reason why a broader understanding cannot be developed within a framework of moduled topics. And, to deter a "learn and forget" mentality, pupils should not be allowed to re-sit modules over and over again.
But he should be more adventurous in his thinking. The school-leaving age rises to 17 this year and 18 two years after. Why then, as the CBI suggests, do we need external exams at 16 at all? Do we not need to encourage the study of a wider range of subjects, like computing and engineering, to encourage innovation and creativity, rather than narrowing the EBacc to some throwback to the 1950s School Certificate in the days when only 7 per cent of school-leavers went on to further education. Should we, as the former Tory education minister Kenneth Baker argues, raise the age of transition to secondary education from 11 to 14 with a choice between academic, technical, career-based and creative or sports schools? For a self-styled education visionary Mr Gove demonstrates a paucity rather than an excess of imagination.
Every education system is unfair to someone. Mixed-ability classes aid social cohesion but can fail to develop the full potential of brighter pupils. All-or-nothing exams at the end of the course disadvantage diligent plodders. Continuous assessment does nothing to encourage high-pressure brilliance. GCSEs disfavour later developers, of whom there are many more boys than girls. AS-levels squeeze out the time in Lower Sixth for school plays, forming bands and tangential enrichment.
And yet the inescapable fact is that good schools make the best of whatever the system is. Instead of just scrutinising league tables parents need to visit schools to see the quality of teaching and assess a school's ability to broaden the mind beyond the tramlines of examinations. And then they need to tell Mr Gove that the real enemy of education is unnecessary political tinkering by people like him.