There was a time, in the not too distant past, when A-levels required 18 months of work and a month of revision - organised by the student with some advice from his or her school - and then straight into a series of linear papers. But the creeping rise of modularity has signalled the end of the traditional A-level, with its narrow academic focus rooted in the grammarpublic school tradition.

The rise of the Easter intensive revision course is a more certain sign of the times we live in. Increasingly, young people and, more particularly, their parents, have become aware of the importance of getting their A-levels right the first time, going to the right university then embarking upon the right career. The cost of failing to get into their first-choice university, first time around, is simply too great. And so the Easter A-level revision business has boomed.

The courses take a variety of forms, although the five-day non-residential has become the standard. And providers are becoming increasingly varied - they include public schools and some of the newer universities.

Students tend to fit into four types. First, there are those who want to turn Bs into As - or they are already A-grade candidates but lack confidence. Second are the genuinely weak who want to turn a D or an E grade into something more respectable. Then there are those who seem to have spent their A-level time in a cloud of confusion and don’t even know which board or syllabus they are studying. Finally, there are the students attending under duress from parents, because it is cheaper than a week’s late skiing and, at the very minimum, the five days guarantee 35 hours solid revision, while loafing around at home for the week will guarantee nothing beyond extensive exposure to the banalities of MTV.

Some subjects, such as economics, physics and maths, which have a considerable common core across all boards, are more amenable to being reduced to a week’s study. But it is sometimes impossible to find much common ground for subjects such as history and English, which have an almost infinite permutation of papers, and classes are reduced to abstract skills-based sessions.

And students’ needs differ. For some, the problem is a simple lack of knowledge; they want a crash course, a summary of the key topics on the syllabus that, for a variety of reasons usually relating to personal indolence, they have missed out on.

Others may be familiar with the syllabus but need to learn essay-writing skills or simply how to structure a good answer. Inevitably classes end up as a compromisebetween these needs.

Do such courses make a difference? Probably, but it is impossible to say for certain as you can’t disentangle the teaching provided by the school from the support offered by an intensive revision course. A student whom I taught last year spent three of the four weeks of his Easter break devoting a week to each subject, at a total cost to his parents of about pound;1,100. He got his three A grades and is now studying PPE at Oxford. He may, of course, have achieved three A grades without the help of the crammer, but the investment reduced the risk of that not happening. Experience suggests that these courses provide focused guidance and prevent time being wasted, while providing a disciplined framework for revision.

Critics argue that the children of wealthy parents are effectively able to buy better A-level grades. This is true - more than 70 per cent of all Easter school applicants come from independent schools, which account for just 18 per cent of A-level students. State school students do attend, but fees of around pound;300 per subject per week mean they are thin on the ground. The market continues to increase at about 10 per cent a year. It is estimated that in 2000 about 12,000 students attended some sort of Easter revision course, paying an average of pound;310 a week. And about 9,000 attended GCSE courses. These are now taking off - a potentially huge market.

It may only be a matter of time before anxious parents start packing off their seven-year-olds to Easter courses in preparation for key stage 1.

Andrew Granath teaches at the Latymer school, Enfield, north London

WHAT DO YOU GET FOR YOUR MONEY

In an unregulated market with no formal quality control or inspection, parents should ask these questions before enrolling:

* How many hours are taught? For a five-day course, you should expect in the region of 35 hours contact time.

* How much? Expect to pay pound;300-400 for five days.

* Is the teaching in small groups? Eight should be the effective maximum.

* Who will be teaching the course? Are they familiar with or currently teaching the syllabus that you want? This is important for subjects such as history and English.

* Will the students receive exam practice?

* What premises do they use?

* Can we discuss what is being taught?

* Will the organisers treat the customer as an individual?

* Can we return after the course for additional help?

* Is the tutor local and can we hire his or her services closer to the summer examination date?

* Is there a brochure? The glossier, and the earlier it is printed, the less likelihood of flexibility.