Siobhan McLornan is doing her A-levels this week at Ballymena Academy, Co Antrim - a modern, 1,300-student school with superb academic and sporting facilities. She would like to go on to study law, either at TCD or Nottingham. She is one of a minority of Northern Catholics who go to largely Protestant state schools.

One impression she retains from her exchanges with students from Carrick-on-Suir, Co Tipperary, is the wide range of subjects, including maths and science, Southerners have to take in the Leaving Certificate. She, on the other hand, was able to drop the subjects she disliked after her intermediate GCSE exams at 16.

Three A-level subjects are quite enough, providing the grades are satisfactory, to get into university. She is one of the relatively rare students who is doing four: history, English literature, classical civilisation and Latin.

One thing she likes about the Southern system is the transition year which most schools do after the Junior Certificate, and which allows students to study computers, new languages, go abroad, do voluntary work or gain work experience.

In Northern Ireland they only have "enrichment courses", in which they can study art or psychology or another language for four periods a week in the year after GCSE, and only then if A-level studies allow. Because she took four subjects, Siobhan had to "plunge straight into A-levels" as soon as she came back to school after her GCSEs.

Another thing she prefers in the Republic is the third-level applications system, which only springs into action after the Leaving Certificate results are published in August. In the North, like the rest of the UK, students apply for third-level places the autumn before Alevel exams, receive provisional offers in February or March based on a mixture of predicted results (by the school), personal statement, interview and even GCSE results. They then know precisely what marks they have to aim for - this extended process, she thinks, increases the pressure on students.

Her impressions of Carrickon-Suir CBS was that it was small and did not seem to have a library. She recalled that the students from Tipperary who came to Ballymena were astonished at the Northern school's sports facilities: its eight tennis courts, three hockey pitches and its "countless" rugby pitches.