Mr Scott said the use of national tests (NAPLAN) to rank schools' achievements on the My School website was too limited, because it only assessed years 3, 5, 7 and 9 and only in literacy and numeracy.

``Use of the data to compare schools can be simplistic and fraught with danger,'' he said.

``Look at the information, but please, talk to your school's principal if you think there is a problem.''

The principal of St Dominic's College, Kingswood, Jeff Regan, also warned people against relying on NAPLAN tests to rank schools.

Mr Regan also said the website was difficult to follow.

``I can't understand much of it, so I don't know how most other people are going to,'' he said.

Penrith High School parent Glenda Browne said My School was of little use to her.

``I think questions parents have are more complex, such as `How do they work with children with special needs?' rather than the simple `What's their maths score?','' she said. ``On the other hand I tend to think that information should be available the challenge is to ensure that it is used well.''

Mr Scott said the website also failed to note that some schools were wealthier than others and able to provide their students with more resources.

Education Minister Julia Gillard

defended the use of NAPLAN tests, saying they provided the best possible guide to students' literacy and numeracy skills.

``My School is not a league table and does not have any mechanisms to create league tables,'' she said.

``If we know which schools are struggling, we have new money and new targeted programs to ensure every one of our schools is a great school and every kid is getting a world-class education.''

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