Ed Balls: Tests are tools to help children achieve the best

Delays in the marking of this year's key stage tests have caused stress and worry for many parents, teachers and pupils. I share their frustration – as a parent, I know how annoyed I would be if my child had been forced to wait weeks longer than expected for their results. Despite the hard work in recent weeks of the Qualifications and Curriculum Authority (QCA), which manages the testing process, there are still delays and its contractor, ETS Europe, has been unable to fulfill its obligations. This is unacceptable and an independent inquiry is now under way, led by Lord Sutherland. But while I am clear how serious the contractual failure has been, I do feel some commentators have lost sight of what our policy on assessment is trying to achieve.

Our aim – and that of schools – is to help all children do the best they can. Tests are simply tools which can help teachers achieve that – as well as focusing everyone on the core skills young people need. Tests also create accountability in the education system. I won't abandon the principle that parents should always have information about the progress of their child, that of individual schools, and government education policy as a whole.

So when this newspaper calls for me to be held account, as it did last week, and demanded to know my plans to improve children's education, I say that test results are crucial to my accountability – as well as that of local authorities and individual governing bodies.

It is only because of national tests, which are drawn up and marked at arm's length from government, that we can see the very real progress schools have made since 1997 in literacy and numeracy at 11 and 14 – and also agree that there is still a long way to go. And because we now have the independent regulator Ofqual, I hope we can end the annual sterile debate that improved results mean "dumbing down". And I am pleased this year that Ofqual has said that – despite the problems – the marking of tests is at least as good as previous years.

But the current national testing system is not set in stone. As we said in the Children's Plan, there may well be changes. The testing system needs to be well run, with results delivered on time. But it could be more flexible for schools, more personalised for individual pupils, and provide more scope for teacher assessment and professional judgment. That is why we are currently carrying out a pilot in 450 schools of "stage not age" tests, which allow children to take shorter tests when they are ready – much like a music exam – rather than waiting until a fixed point at 11 or 14.

This pilot is about more than testing. It is a whole new way for teachers to track pupils' progress by interweaving tests with their ongoing assessment and working out from day-to-day what level each child is working at. If they think they are falling behind, then children can get one-to-one catch-up tuition in English or maths. Once a teacher is satisfied that a pupil is working confidently at a level, the pupil takes a test.

The tests will acknowledge each step a child makes so that pupils, parents and teachers are always reaching for next level – whatever the ability of the pupil. Brighter children can race ahead to the top levels, and all pupils are supported to reach their full potential.

I'm attracted to the testing-when-ready principle but I'll only implement it following a rigorous evaluation of whether it helps children make faster progress. Far from abandoning independent assessment, I hope the new tests will allow parents to get much more useful information on how their child is progressing – instead of just snapshot results after two or three years.

This is just one of a series of reforms we are planning which will help children progress – including the Rose review of the primary curriculum, and raising the education leaving age to 18. Also this year 20,000 students will be the first to do one of the new diplomas – and some of the country's most famous universities have now said they will consider applicants with a diploma.

So while administrative delays in marking this year's tests and getting the results to schools have been unacceptable let us not lose sight of the bigger picture. We have made huge progress made since 1997 because we have used testing as one lever to drive up standards. Alongside our wider reforms, effective assessment will continue to drive up standards in the years to come.

The writer is Secretary of State for Children, Schools and Families