The 45-minute tests to be taken on entry to secondary school would be used as a basis for "value-added" exam league tables.
Both the Government and Labour have said they want value-added tests but neither has worked out a way of devising them. Schools say the league tables to be published this month are unfair because they do not make allowances for differences in intake.
The new tests may eventually be used in all private schools and would allow them to measure the progress their pupils have made between entering secondary school at the age of 11 or 13 and GCSE and A-level.
State school pupils now take national curriculum tests at seven, 11 and 14 and the Government is considering how to use the results to compile value-added tables. A paper considered by the anuual conference of the Girls' Schools Association of top girls' independent schools in Brighton proposes a test that would measure IQ, potential, and achievement.
Roseanne Randle, chair of the association's education committee and head of Dame Alice Harpur School, Bedford, said: "What we are planning would be much better than the Government's national curriculum tests. We think the Department for Education would look at our tests with interest. They could lead the way to a sensible national scheme.
"The reason many independent schools are not taking part in national tests is that they don't think they are very valuable."
Some independent schools will pilot the tests next September and all may take part the following year. The Headmasters' Conference of top boys' public schools is also piloting the tests. Margaret Rudland, the association's new president and head of The Godolphin and Latymer School, Hammersmith, west London, said test results of individual pupils would not be released. "I see no value in ranking pupils on their entry to school," she added. In her presidential address Mrs Rudland attacked the idea, floated recently, of introducing a moral component to every A-level subject.
She said: "Honesty and integrity are more likely to be learnt through the systematic study of an objective discipline, such as mathematics, than by threatening its intrinsic integrity with a superficial overlay of morality. While arguing for breadth the association has always insisted on rigour in the sixth-form curriculum and we need to preserve the intellectual identity of each subject as a priority.
"Surely a really detailed study of a subject provides a kind of moral and cultural dignity of its own. Perish the thought that moral instruction will be included in every A-level course."Reuse content