So a new method for judging schools is to be tried. The Government is to investigate introducing a “report card” system through which schools could be graded A to F based on their performance across many aspects of school life.

Modelled on a regime that has been operating for a year in New York City, the report card system could be introduced here by 2011. Officials at the Department for Children, Schools and Families are reportedly enthusiastic about the potential of this new accountability measure. It is even thought that, if they take off, a Labour government - should it still be around after 2011 - might one day use them instead of traditional school league tables.

One can understand why some of the teachers’ unions are looking on the cards as a potentially positive development for their members. They offer, potentially at least, three major benefits over league tables: the chance for aspects other than exam results to be factored into judgments about a school’s quality; the ability to highlight the results of “vulnerable” groups, such as special needs pupils; and the capacity to factor complex statistics, which recognise the circumstances facing individual schools, into a simple A to F judgment.

So far, so progressive. But this is still a league table. And it still runs the risk of reinforcing the test-driven, data-obsessed system that has bedevilled English education for 20 years now.

The reasons? First, this will still be a statistically driven regime in which exam results will, surely, still play a large part in determining a school’s overall outcome.

Second, as now, schools will feel forced to play the system - analysing the statistical route to success under the formula and then tailoring provision accordingly. This may or may not be in students’ long-term interests.

Third, how realistic is it to judge any institution on a single “outcome” scale? Secondary schools, for example, are complex places, with scores of teachers of, no doubt, differing quality, and hundreds of pupils taking a wide variety of courses.

Fourth, giving schools a single grade helps underscore the idea that there are vast differences between them. But is this really the case? In fact, there are striking similarities between schools: all pupils take the national curriculum and are taught according to national teaching strategies by a workforce trained to government-approved methods. If they are different, how much of this is down to the characteristics of their students, rather than the schools themselves?

All of these objections are conceptual ones that could be made to any league table system. And I believe that such arguments should be made a lot more strongly than they have been in the past.

I believe - and you might well respond, “Who is he to say this?” - that the past 20 years have seen league table debates conducted very much on the Government’s terms. Instead of questioning the fundamental difficulties with statistically driven rankings, the debate has too often focused on their design. This has led us from “raw results” tables, to value added, to contextual value added, and now to report cards. Yet the serious underlying objections remain.

Realists will say that abandoning league tables will never be politically possible. To which I would reply: rejecting league tables does not mean rejecting accountability or the notion of providing information on school quality to parents.

My solution would be for ministers to allow the publication of exam information for parents, but not to endorse it by publishing it officially. Ofsted inspections - based on a proper, qualitative look at both the school and the quality of information it gives to its community - would become the main way for parents to judge the quality of an institution.

These rankings should be investigated. But the deeper issues will not go away.

Warwick Mansell, TES reporter and author of ‘Education by Numbers: The Tyrrany of Testing’.