England's test regulator has recommended radical changes to national test marking amid concerns that the current system overestimates pupils'
The Qualifications and Curriculum Authority has advised ministers that the method for double-checking pupils' scripts needs to be replaced because of a technical bias towards inflating scores.
Since the tests were instigated in the early 1990s, the QCA has operated a system of "borderlining" of some key stage 2 and 3 test scripts, taken by 1.2 million pupils a year.
Every pupil's paper is marked at least once. After the first check, senior examiners meet to consider how pupils have performed, before setting mark boundaries.
Once these thresholds have been set, they look again. Pupils whose scores fall just below each level threshold are re-marked. Those falling just above are not.
The system, which operates mainly in the English tests, was introduced to ensure that pupils are not being unfairly denied a level. But critics have argued that it inflates the overall national scores. The re-marking process always results in far more pupils gaining a level than losing one, because only those just below a level threshold are selected for re-marking.
A KS3 English marker told The TES: "Borderlining isn't an objective exercise to check the accuracy of levels; at best, it checks whether students can be moved up."
The examiner, a first-time marker, also said problems he experienced with this year's tests had changed his views from "evangelism" for the assessments to deeming them worthless.
He said the papers he was given to mark were not the ones he had asked for, and that his marking deadline had been put back because of delays in checking the quality of his work.
And he thought the mark scheme had been so poorly thought through that perfectly good answers had to be given no marks. Teacher assessment was probably more accurate, he said.
Sir Anthony Greener, QCA chairman, has written to Ruth Kelly, Education Secretary, advising her that the system should be scrapped. The letter did not set out in detail what might replace it. But possible ideas include double-marking all scripts and marking scripts which fall both just above and just below a level threshold.
The borderlining controversy comes with the test scores under fresh scrutiny this year. Pupils only need 22.5 per cent to score a level five in the hardest of four KS3 maths papers, taken by pupils expected to achieve level six to eight. Last year, the figure was also 22 per cent.
An Edexcel spokesman said the board could not comment on mark scheme issues or the borderlining system.
A QCA spokesman said up to two per cent of KS2 and 3 English papers gained a level as a result of borderlining. Commenting on the marker's complaint he said: "Obviously it's unfortunate if someone has had a bad experience.
But there are a number of experienced English teachers who come back year on year to mark these tests."