While critics on the political right accused him of giving in to the demands of teachers who had complained of overwork and of a too-rigid testing structure, some teachers' trade unions said he had not gone far enough.
Sir Ron, chairman of the Schools Curriculum and Assessment Authority, has advocated a slimmed-down curriculum, simplified testing, and the possible abolition of the 10-level scale on which pupils are assessed.
But while some aspects of the report won almost universal praise, others look set to cause more controversy.
The issue of league tables measuring the progress made by pupils looked certain to be among the main sticking-points. Sir Ron went outside the remit he was given by John Patten, the Secretary of State for Education, to say that the Government should consider league tables that take account of the different catchment areas of schools.
Yesterday he suggested there might be no need for league tables at all. Parents could compare different schools' performances by reading prospectuses. But ministers are determined to publish the results of 11- and 16- year-old tests nationally.
Sheila Lawlor, deputy director of the right-wing Centre for Policy Studies, said parents should be able to compare their children's results with others in their area and with the national average. Any attempt to gauge whether a school's results were better or worse than might be expected would result in a 'Kafka- esque' bureaucracy, she said.
But Doug McAvoy, general secretary of the National Union of Teachers, said his union would not accept league tables in any form.
Sir Ron drew a distinction between teacher assessment, which would be used to reveal individual pupils' strengths and weaknesses, using a bank of material upon which staff could draw, and formal tests which could be used to compare one school's performance with another.
But Mr McAvoy said any such formal tests would be educationally flawed. 'These tests will not inform parents about their child's development nor will they assist teachers in diagnosing pupils' educational needs.'
Teachers' unions were also unhappy with the suggestion that some of the formal tests could be marked externally, saying that this would cost millions of pounds and would deprive them of valuable information about their pupils. Sir Ron said yesterday that external marking could only be considered either for 11-year-olds or for 14-year- olds, because to introduce it for both age groups would be prohibitively expensive.
Further controversy is likely to arise when a full-scale review of each subject begins. This is likely to happen early next year after Sir Ron produces his final report, with all the 10 subjects in the National Curriculum likely to be reviewed at once.
Yesterday's report suggested that the content of each subject should be reduced, but the interests of individual subject lobby- groups are likely to come into play as the details are discussed.
However, the report won praise from all quarters for attempting to reduce the content of the curriculum and to reform the 10-level scale through which pupils are meant to progress. Plans to cut the amount of time pupils spend being tested to two hours for seven-year-olds and six and three-quarter hours for 14 year-olds were also welcomed.
At present, a primary school teacher might have to judge pupils against a total of 1,000 National Curriculum 'statements of attainment' in a single year, Sir Ron said. He suggested that teachers were not required by law to do this and that they should use their own judgement when assessing pupils.
His report said that the National Curriculum should take up to 90 per cent of pupils' time up to the age of seven, while they concentrated on literacy and numeracy, but that it should be reduced to about 75 per cent by the age of 14. English, maths and science will still take up large amounts of pupil time, but in other subjects much of the content will become optional.
Sir Ron suggested two possible options for the 10-level scale, which has been criticised for distorting subjects like history and English, forcing teachers to teach increasingly sophisticated skills instead of a body of fact.
It might be improved by trying to iron out imbalances between the different levels, he said, or it might be replaced by a system under which pupils were given a GCSE-style grade for progress at the ages of seven, 11, 14 and 16. The suggestion that the scale might be scrapped was welcomed by Lord Skidelsky, an outspoken critic. 'It would get rid of the sense of fake objectivity which seems to dominate the 10-level scale.'
Rare praise was also forthcoming from some of the teachers' unions. Peter Smith, general secretary of the Association of Teachers and Lecturers, said: 'Sir Ron Dearing has shown throughout his deliberations that he is prepared to listen to the teaching profession. This interim report must translate into real action by the Government to solve the problems of overload in the curriculum and testing.'