Professor Lindsay Paterson of Edinburgh University repeated his familiar view that comprehensive education had a number of successes to its credit in Scotland - better staying-on rates, improvements in achievements by girls and Catholics, a broader curriculum and a reduction in class differences between schools.
Douglas Osler, senior chief inspector of schools, also endorsed comprehensives but told the Northern Ireland group, which is on a fact-finding visit throughout the UK, that the Scottish system was not perfect. It was, however, moving away from the uniformity of the early days.
"To me, a comprehensive school is simply a centre of learning that serves the community," Mr Osler said. "Once the pupils are there, a variety of things can be done in relation, for example, to special needs, the organisation of S1-S2 classes, the range of courses, and so on."
New community schools, with their emphasis on addressing all the needs of the child, would be "the comprehensive schools of the future", Mr Osler believed.
Brian Boyd of Strathclyde University agreed that there had to be less uniformity in teaching and more emphasis on "creativity, innovation and flexibility".
The comprehensive debate has been reignited across the UK following the shake-up pledged for secondary schooling in England in an offensive against "the bog standard comprehensive", as it was described by the Prime Minister's official spokesman.
Professor Paterson said the debate was bedevilled by misinformed critics. He singled out for particular scorn Tim Luckhurst, a former Scotsman editor whose children atend independent schools and whose wife is a prominent Tory.
In a column in the Belfast Telegraph, as part of Northern Ireland's "11-plus debate", Mr Luckhurst cited the "rigorous" international maths and science study showing Scottish pupils near the bottom of the league among countries belonging to the Organisation for Economic Co-operation and Development.
Pupils from Northern Ireland's grammar schools win twice as many places at leading universities as Scottish pupils, Mr Luckhurst claimed, which was further evidence in favour of the "meritocracy" of allowing schools to select by ability. Professor Paterson said such charges simply plucked figures out of the air and out of context.
The performance of pupils in the "unreliable" OECD study at the arbitrary ages of nine and 13, and the much-cited problems of S1 and S2, had to be set against evidence that they catch up later: the proportion of 21-year-olds who complete higher education courses is 46 per cent, well ahead of England's 28 per cent.
University statistics, he said, ignore the significant role of FE colleges which account for half of all entrants to higher education in Scotland, compared with 25 per cent in Northern Ireland, 13 per cent in England and 5 per cent in Wales.
The contribution of FE is also one of the reasons figures tend to show that fewer Scottish students from working-class homes go to university, Professor Paterson commented. They are "creamed off" by the colleges. It does not reflect a failure of comprehensive education.
Dr Boyd said the next step for comprehensives was to embrace the notion that pupils had "multiple intelligences". He still came across teachers who categorised children as "bright" or "thick". Secondary teachers in particular ought to think more about learning than teaching.