Years ago, when only the " academic elite" did exams (O and A-levels), the quality of students was assessed by exams taken at the end of the two-year course and grades of achievement were awarded according to the results.

As a teacher you'd make sure you revised first year work before the exams so that your students would be ready to be tested on the results of two years' study.

Then, when exams were changed to take in a much wider ability range than the old O and A-levels, we began to hear plaintive cries of "he's no good at exams" or "he gets too nervous" and calls came for an element of coursework to be introduced into the exam system.

Critics of the coursework idea pointed out that, rather than helping the disadvantaged child who had no history of exam taking (which it was designed to do), it would instead favour the middle-class child, who had books in the home and caring, educated parents who could help with the work or pay for private tutors.

These caveats, however, were ignored, I suspect because teachers relished the idea of deciding themselves what was taught, what was set as assignments, marking it themselves and not trusting their pupils to the impartial judgment of outside examiners, and therefore pushing up their pupils' grades.

Of course, in their zeal to take control, it never occurred to them that all this extra setting and marking would push up their workload enormously, since they were, in effect, just acting as unpaid markers for the examining boards who, in the past, had had to pay people to mark exams.

At the beginning, the rules for coursework were rigid and clear.

In English, for example, ten pieces of work had to be produced over the two years of the course, each piece testing a specific skill - a formal letter, a factual piece, a piece of creative writing etc - and at least three of these pieces had to be produced "under controlled conditions" - ie, done as tests in class rather than at home.

Children were not allowed to do a piece, have it marked by the teacher, and then re-do it to try to get a better grade. For every piece less than the required ten offered, ten per cent of the marks would be deducted.

Of course, it wasn't too long before these rigid rules were considered unworkable by teachers and were abandoned.

Schools found it difficult to get some pupils to produce ten pieces of work, so the demand for ten pieces was relaxed.

Similarly, for a teacher to tell a class that a coursework test was coming up often led to half the class staying away for that lesson. So, fearful of having large numbers of children who get no grade at all because of failure to complete the course work, this element also fell into disuse.

As for teachers being forbidden to mark work and let the children improve it to get a better grade, the teachers got round this by marking the work only in pencil, because, they argued, this didn't count as real marking, and soon most schools adopted this method.

All the schools attended by my private students did this. Now, of course, a new nightmare had appeared - the buying of essays on the internet, or cribbing them from internet sites, both by school and university students.

Thus we go another step along the road of grades being an entirely false indication of the quality of the candidate being awarded those marks.

Schools know it happens, universities know it happens, but no really serious attempts to prevent such fraud appear to have been taken.

Good results, it seems, are more important than honesty.

I'm not normally given to believing conspiracy theories but I have a sneaking suspicion that relaxing coursework rules, letting teachers mark the work of their own students, allowing pupils to present cribbed essays, allowing a pass at GCSE maths at 17 per cent, and giving enhanced percentages if a child's parent or pet dies before the exams, is just a way of ensuring that, no one fails, so that governments can point to steadily rising pass rates as proof that education policies are working.