Aust lags world's best on student gap

Australia is lagging behind the world's best when it comes to teaching, with a new report showing a six-year gap between the most and least advanced students at any given age.

The Grattan Institute report says the system fails to stretch the most advanced students or support the least advanced students.

The Melbourne-based think tank suggests the national rollout of a highly-regarded NSW program to the bottom 20 per cent of primary schools at a cost of about $300 million a year.