Teachers, by and large, are suspicious of national tests. Exams, they say, distort the curriculum by emphasising measurable skills over more important but less obvious ones. Preparing for tests uses valuable teaching time which could have been spent on something more creative or challenging. Young people who do badly can have their confidence affected for life - why rub their noses in failure?
John Dunford, general secretary of the Secondary Heads' Association, has declared that testing 14-year-olds at the end of key stage 3 is a waste of public money. Most schools, he says, examine their pupils regularly anyway. This may now be true - but in the good old days before the national curriculum and its tests, many did not. The grammar school routine of yearly examinations was dropped by many secondary schools when they went comprehensive.
This meant that a large number of young people first experienced the rigours of the exam hall when they sat their O-levels or GCSEs. They had not had any previous practice in organising their revision, handling stress, or working under pressure - all useful attributes for adult life.
The critics of testing often miss the other significant functions fulfilled by the KS3 tests. First, they are becoming established as a rite of passage, a common experience shared by every 14-year-old across the country. Second, they give important feedback to young people, enabling them to improve their performance in the future. Teachers are fond of saying that key stage test results only tell them what they know already; but young people and their parents also need explicit information on their progress.
Third, national testing is a national event. The whole country is becoming more involved in education - especially where GCSE and A-levels are concerned. Home study guides and revision aids appear in bookshop windows; TV presenters make jokes about revision fever. Adults begin to take an interest, however vicarious, in the progress of the younger generation. This is all to the good, and signals the shift in culture which David Blunkett so desperately wants to see, and which will make teachers' jobs much easier.
So despite some educators' misgivings, tests at 14 do have a role at a critical stage in young people's development. They transmit to schoolchildren the crucial message that, whatever your mates may say, academic achievement does matter.