72,000 pupils in grades bungle

Up to one in six pupils may have been awarded the wrong grade in national curriculum science tests, according to a report published yesterday.

The report, published by the new exams watchdog Ofqual, revealed that over the past five years between 12 per cent and 17 per cent of pupils were awarded the wrong level in the science tests for 11-year-olds.

The findings emerged as both teachers and heads are gearing up for a boycott of the tests in science, maths and English taken by 600,000 children next May. Ofqual ordered an investigation into the reliability of national curriculum SATs results across all subjects after Professor Dylan Wiliam, of London University's Institute of Education, warned that as many as 30 per cent of 11-year-olds may have been awarded the wrong "levels", or grades.

The test results are used to measure the performance of every primary school in the country in government performance league tables. Yesterday's report, research for which was carried out by the National Foundation for Educational Research, is the second study of national curriculum test results carried out by the exams regulator.

The results showed an improvement with 83 per cent of pupils being given the correct level in 2004 and 88 per cent last year. But around 72,000 children would have been given the wrong level.

The findings will add weight to the claims by leaders of the National Union of Teachers and the National Association of Head Teachers that the results are meaningless and unreliable.