Either way, it makes a good story. We are aided and abetted in our obsession by politicians and an older generation which refuses to admit that the young are just as bright and hard-working as their parents and grandparents. Surely things ain’t what they used to be.

Governments feel obliged to show that they are, and, during the past decade, they have engaged in relentless investigations of “standards over time”. The Qualifications and Curriculum Authority has just produced the latest batch of 12 subject reports, with predictable results. “Standards of science exams have dropped,” said The Times, focusing, like most newspapers, on the one subject where the watchdog found signs of decline.

Ken Boston, the authority’s boss, retaliated with a letter saying that the reports “clearly showed standards have been held at a consistently high level over many years”.

Neither gives a true picture of what has really happened to exams. Dr Boston is right to insist that there is no evidence in general that things are getting worse. But some of the reports look back over the past 20 years and exam boards no longer have candidates’ scripts. It is impossible to make a real comparison between the value of an A grade then and now.

Nor does it make much sense to try. It isn’t that exams have got easier or harder but simply that they - and education - have changed. The report on GCSE English literature between 1980 (when the 16-plus exam was O-level) and 2000 sums it up. In 1980, it says, candidates were expected to learn texts in detail by memorising quotations. By 2000 they were allowed to take texts into the examination room and questions were based on interpretation and critical response. Questions often used phrases such as “What do you think about...?”

Thinking was not a priority in the old O-level exam. I remember learning by heart the causes of the French revolution and duly regurgitating them in answer to the question: “What were the causes of the French revolution?” A contemporary GCSE history paper with all that source material (“How useful is source D to a historian studying the impact of turnpikes?”) terrifies me.

I asked a senior examiner who has marked GCSE and A-level English papers for 25 years whether she thought standards had deteriorated. She replied that, even among the brightest candidates, spelling, grammar and punctuation had probably slipped a bit but that the sophisticated analysis and criticism of today’s sixth-formers made her own A-level essays look shallow and pedestrian.

Modern exams emphasise different skills from those required a quarter of a century ago. The problem with GCSE science is not that “standards have dropped” but that the demands have not changed enough. A report from a committee of MPs earlier this year said that the GCSE science curriculum was overloaded and put too much emphasis on learning facts (compare and contrast with English). Practical work was dull, tedious and pointless.

Professor Adrian Smith’s inquiry has suggested that maths lessons and exams should also be reformed so that less able pupils can see the point of them.

Boring lessons are the real enemy of standards. A hundred “standards over time” reports will contribute not a jot to pupils’ progress. Fewer facts and more questions in science would really make a difference.