Indeed, in science, that dubious honour goes to Northern Ireland, which had the largest gap between the 95th and 5th percentiles of all of the 57 countries. The report from the Programme for International Student Assessment (Pisa) suggests that this "may reflect the fact that Northern Ireland has a selective education system".
Whether Scotland has the largest gap of the OECD countries is not the issue. The issue is the effects of selection, whether internal (Scotland) or external (Northern Ireland). In the section of the report on Scotland headed "The influence of socio-economic status on mathematics performance", the authors suggest that "young people from the lowest socio-economic backgrounds in Scotland perform well below their peers in the Netherlands, Korea and New Zealand" (page 61).
Given that these young people are likely to be in the lowest sets in Scottish secondary schools, and that the research evidence on setting is, almost universally, critical of the practice, surely it is time to revisit this issue if we genuinely want to close the gap in achievement?
Northern Ireland may soon be taking the first steps towards "comprehensivisation". Perhaps we in Scotland, having embraced the comprehensive ideal with some success, now need to take the lead and deliver equity in education for all of our young people.
Brian Boyd, professor of education, Strathclyde University.