The mid-1990s saw two striking reforms of the Irish educational system: the scrapping of undergraduate fees and the incorporation of Transition Year into the mainstream curriculum of second-level schools. The first, superficially dramatic move will almost certainly be reversed early in the new century.

The second may turn out to be the most genuinely radical initiative of the decade. Its genesis goes back to 1974 when the then Minister for Education, Dick Burke, said there was a need "to stop the academic treadmill and release students from competitive educational pressure for one year". Three schools and 66 students in Dublin, Tipperary and Mayo piloted such a year.

By the early 1990s, 150 schools and more than 8,000 students were pursuing an optional Transition Year.

When a commitment to provide a six-year cycle at second level was re-inserted in the 1991 Programme for Government, it started to become clear that the only way for many schools to offer a three-year senior cycle (not including a repeat Leaving Certificate) was to offer a Transition Year programme.

By September 1994, the first year in which it was offered as an option to all schools (complete with a Statewide teachers' in-service programme and a special £50 annual grant per pupil), there were 451 schools and more than 21,000 students in the programme.

This rose to 510 schools and 24,650 students by 1997-98 - about 37 per cent of the total enrolment - before falling back slightly to 502 schools this year. Its aims are defined by Department of Education guidelines as "education for maturity with the emphasis on personal development"; skills development "with the emphasis on interdisciplinary and self-directed learning" and education "through experience of adult and working life".

The revolutionary nature of Transition Year lies in its uniqueness as the first ever Irish curriculum programme to be devised, delivered, assessed and evaluated by the schools themselves; and in its harnessing of the non-academic "multiple intelligences" which schools traditionally place little value on. "It is an incredibly farsighted programme - helping 15 and 16 year olds move from the dependency of childhood towards the independence of adulthood," says Gerry Jeffers, head of the Department of Education's Transition Year support service.

"It is all about maturing. If Transition Year works and young people become independent learners, they will have that skill for life." He says the full benefits of the year won't be seen until much later; for example, the stronger study habits which the year fosters will help to reduce third-level drop-out rates. The year, Jeffers adds, has attracted interest in places as far apart as Scandinavia and the US.

For the programme to work properly, it has to have four elements, Jeffers says. First, there are the high profile "once-off" events, such as work experience and foreign and outdoor pursuits trips.

Second are the projects and courses which are specific to Transition Year, such as students setting up "mini-companies" - one of the programme's most prominent success stories. The activities unique to Transition Year also include European studies and environmental modules, such as the highly praised "Shaping Space" programme on the built environment.

Third there is the opportunity to sample new subjects - from extra modern European languages to physics and chemistry - with a possible view to continuing them into the Leaving Certificate years. (However, the Transition Year programme's complete separateness from the Leaving Cert programme is continually stressed.)

Ideally, it gives less academic students a chance to catch up academically and more academic students a chance to develop new areas: for example, it gave the brilliant winner of the Young Scientist competition, Sarah Flannery from Blarney, Co Cork, a chance to pursue her interest in data encryption.

Fourth, there are opportunities to study the "core" subjects in more imaginative ways: for example, by doing media studies in English, or studying packages like the one launched recently based on the Telefis na Gaeilge soap Ros na Run in Irish.

Transition year demands a huge amount from its school co-ordinator and other involved teachers. Staff-rooms often are often divided.

On the one side, there are the teachers who feel constrained by narrow subject teaching and liberated by the programme's huge potential for independent action; on the other side are more traditional teachers who feel threatened by the prospect of such independence - and by difficult new concepts such "negotiated learning", in which pupils have an input into what they learn.

Those who take on Transition Year often do it with missionary zeal, and there is a real risk of "burn-out" because of the workload and constant experimentation it involves.

The Department of Education emphasises the importance of a "whole school" approach, but it is not clear this is happening in many schools.

Where schools make it optional - and especially when they offer it only to academically weaker children - it can often seriously divide the energy of the teaching staff.

Generally, the factors governing the success of Transition Year are the size of the school, and therefore the breadth of the curriculum on offer, the commitment of the teachers and the involvement of as many students as possible.

The schools with the highest take-up are community and comprehensive schools and girls' voluntary secondary schools. The lowest are all-boys' schools, with their traditional suspicion of "soft" non-academic subjects, and small rural vocational schools, which simply do not have the resources. With a wide range of new courses like Leaving Certificate Applied and Leaving Certificate Vocational competing for similar resources and demanding similar energies from teachers, smaller schools often opt for these more practically oriented programmes rather than Transition Year.

Maura Clancy, the assistant chief inspector in charge of Transition Year, suggests this is probably one factor explaining the slight dip in the number of schools taking it this year.

Anecdotal evidence from parents suggests that Transition Year is an excellent experience for young people who are already self-motivated.

For less motivated teenagers, particularly boys, it can be more problematic: its lack of structure and discipline may lead to loss of study habits, drifting off into part-time jobs and occasionally not even turning up for the third term.

"It is better to have no Transition Year at all than one which is badly managed," says one parent whose work also takes her regularly into second-level schools.

"The strengths of Transition Year are also its Achilles heels," Clancy says. "Schools are given total autonomy, but the downside is that the programme is as good as the school which is designing and delivering it. "There is freedom from public exam pressures, but if schools don't take seriously the requirement to assess their pupils, the programme can lack academic rigour."

She admits more work is needed on finding effective ways of helping schools to assess and examine the year's work. On the positive side, those teachers learning how to assess portfolios, for example, are gaining a skill which will be of obvious value in the coming era of school-based assessment.