By Mike Baker Education correspondent, BBC News

Like the arrival of security fences around schools, the safety bans on playing conkers in the playground, and the disappearance of the one-third of a pint milk bottles from break-times, this week's announced changes to coursework mark the end of an era of innocence in education.

When the GCSE came in two decades ago, coursework was the bright new idea. It was a core part of the assessment in almost every subject.

Coursework offered a new approach - teachers and students were to be released from the straitjacket of against-the-clock, memory-test examinations.

Instead students were given the chance to develop and display their skills, stamina, interest and extended knowledge of a subject instead of simply jumping through the hoops of memory games and exam technique.

There are now serious pressures that make it very difficult to maintain a level playing field for coursework.

I had personal experience of coursework. In a brave experiment, the school I attended jettisoned English literature O-level in favour of its own qualification, based on 100% coursework.

Instead of plodding through the three or four set texts, and regurgitating gobbets of knowledge in the exam room, we were released to read much more widely. Instead of cramming our thoughts into a two-hour exam, we were able to write an extended essay on authors of our choice.

I chose Orwell and read almost everything he had written: essays, journalism, and novels. It inspired me to take English at A-level and university and to go for a career in journalism.

Innocent days

Somehow I doubt whether the traditional English O-level would have done the same.

But those were more innocent days. My school did not have to worry about league tables or exam targets.

Back then, parents did not expect to be routinely involved in helping with coursework. And, of course, there was no internet with model coursework answers for easy downloading.

This was still true when the GCSE launched and coursework became the norm in all schools.

Since then, though, much has changed. What began as an inspired and liberating educational initiative started to become a burden on teachers, pupils and parents.

Doubts grew about the uneven approaches to coursework across different schools and different teachers. And a market developed in "model", and even tailor-made, coursework answers for sale on the internet.

It is a great shame but, as the Qualifications and Curriculum Authority has concluded, there are now serious pressures that make it very difficult to maintain a level playing field for coursework.

These pressures include, says the QCA, league tables, exam targets and performance-related pay.

When I think back to my school days I doubt very much if my inspirational English teachers had to think too much about whether they, or their department, were hitting targets. They just wanted us to share their own passion for literature.

I am sure today's teachers want that too but they face so many other pressures.

Goodbye to coursework

So coursework will largely disappear, at least as we have known it. That is a shame for pupils who get nervous under exam conditions, and for teachers and students who want to expand their knowledge and skills beyond set-books and course modules.

Yet it is also understandable. Many of us have heard stories about parents who have done much of their children's coursework for them. Or about teachers who keep returning coursework until it is perfect.

Take the former independent school pupil who emailed the BBC to tell us of his experiences. He wrote: "Teachers would often ask for a final draft a few days before the actual coursework deadline. They would then annotate the drafts with 'suggested' additions.

"If one included all these additions in the final piece of work, more often than not that person scored full marks."

Or as a current student wrote: "Cutting and pasting from the internet is a regular occurrence."

The QCA has said that, with the exception of practical subjects such as art, design and technology, music and PE, it may now be necessary to ditch coursework entirely.

Unanswered questions

However there is still a possible compromise - "controlled assessments".

Although the QCA does not spell out exactly how this would work, it would probably involve coursework assignments being set by the exam boards not by teachers.

Moreover, students would have to write up their assignments at school while under supervision.

This leaves many questions unanswered. Would there still be time limits on these supervised sessions? How many pre-prepared notes and materials could pupils bring with them?

And, on a practical note, just how would schools release teachers to supervise these lengthy sessions?

There is a further concern: Will there be enough exam markers to cope if large amounts of teacher-marked coursework are replaced by externally marked controlled assessments?

There is, after all, already a shortage of markers. Finally, more marking would also mean even higher exam fees.

Yet, these important practical concerns aside, the changes announced this week mark the end of an era.

While many will accept the QCA's conclusion that the old-style coursework is no longer sustainable in today's changed world, others may feel that too much would be lost if coursework were abandoned altogether.

If the QCA decides to revert entirely to traditional exams, that would ring alarm bells for those developing the new specialised diplomas. These are due to start in 2008 and are supposed to include an extended essay or project.

If the QCA concludes that coursework, even under "controlled" conditions, is not valid and reliable, where would that leave the diplomas?