New-style tests show that results in science are up to a third lower at the end of primary school than previous scores suggested.
The figures – based on a small-scale “sample” designed to give a more accurate picture of national achievement – will fuel fears that pupils have been “taught to the test” to boost schools’ positions in league tables at the expense of a proper understanding of the subject.
It will also cast fresh doubts over Labour’s education record and raise questions over standards in other core subjects such as English and mathematics.
In the past, all children in England took Sats tests in science at the end of primary school.
Last year, almost nine-in-10 reached the standard expected for their age and 43 per cent exceeded national targets.
But the science test was scrapped following complaints that schools drilled children to pass by repeatedly forcing them to sit practice papers, undermining their education.
It was replaced with a sample test taken by just one-in-20 pupils nationally.
Under the new system, individual schools are not identified and results do not contribute towards league tables.
Figures published by the Department for Education show that 81 per cent of 11-year-olds reached the national target for their age group – Level 4 – in the sample test. This compared with 88 per cent of those who took Sats last year.
It means fewer children can use tables and bar charts to record measurements, identify organs in the human body and understand the difference between solids, liquids and gases.
At the same time, only 28 per cent gained an elite Level 5 in the sample test, compared with 43 per cent last year – a drop of around a third.
Prof Alan Smithers, professor of education at Buckingham University, said: “With these sampling tests, the schools are not individually identified so there isn’t the same pressure to artificially inflate the result.
“When rewards and sanctions are attached to the test, teachers can push up results simply by training children in the sort of questions that will come up and scores quickly get out of line with the actual understanding of the children. In a sense, sampling provides a more accurate picture.
“If we want to discover how well the education system is going, this is the way to do it.”
Statisticians from the Department for Education admitted that the results this year could not be compared with those of the past because previous tests “fed the school accountability framework”.
Ministers have refused to axe Sats tests in English and maths and the latest results will fuel speculation that results in those subjects are also artificially higher.
Michael Gove, the Education Secretary, has already announced a review of the way primary school pupils are assessed.
Christine Blower, general secretary of the National Union of Teachers, said: "The sample tests point the way forward and I urge the Secretary of State to conduct his review of national curriculum assessment with a view to putting the sampling system in place for both English and mathematics."
The sample science test results are also lower than teachers’ own assessments of pupils’ abilities in the classroom.
Teachers informally assess children’s grasp of English, maths and science throughout the final year of primary education, with results being published alongside Sats scores.
Assessment scores released last week suggested 85 per cent of children were at Level 4 and 37 per cent were at Level 5.
--By Graeme Paton, 10 Aug 2010