The c4 programme proved nothing of the sort. A recent report in The Economist (no left wing screed that) showed that standards and attainment were higher in countries where children weren't separated into ability-based schools. So in comprehensive Finland, which has the highest levels of attainment in the world, the differences between schools are remarkably small compared with the UK. So why are they good? The teachers are excellent, and have the flexibility to be entreprenuerial and flexible in what they teach. Impossible to mimic Finland, for various reasons, but segregation according to ability does not lift overall educational levels.