"`There is a problem of perception that we will have to address quite radically," he said.
The Advanced Higher would have to be resolved quickly. Glasgow youngsters could be further disadvantaged if the new qualification was seen as standard entry to university.
"In Glasgow, a lot of young people in their fifth and sixth year do find it hard to get Highers in their fifth year. They take time and gather more Highers in sixth year. This is something that is not registered well in national statistics," Mr Corsar said.
"If they are taking two years to go from Standard grade to Higher, what is Advanced Higher going to do if it becomes the gold standard for entry to higher education? I would like to see clarification and wider equivalences included.'' If the Advanced Higher were to become the recognised entry qualification, it would have serious implications for schools right through the curriculum from upper primary. It would also place Standard grade exams in jeopardy, he said.