The NSW Greens say national literacy and numeracy tests shouldn't be used to rank schools online because it damages education outcomes and stresses children.
The National Assessment Program - Literacy and Numeracy (NAPLAN) begins across Australia on Tuesday for students in Years 3, 5, 7 and 9.
Primary school children will sit four tests covering numeracy, reading, writing and language conventions while high school students will sit five tests, including two tests in numeracy.
Data from NAPLAN is used to rank schools on the government's My Schools website.
Greens MP John Kaye said the benefits of the tests were being undermined by the My Schools website.
"The My School website puts unreasonable pressure on teachers to prepare their students and compromise the diagnostic value of the test," Dr Kaye said in a statement on Tuesday.
"Along the way, educational outcomes are being compromised and children are unnecessarily suffering stress."
He said the "high stakes" of the tests had "driven schools and parents into a frenzy of preparation that robs the rest of education of time and effort".
He urged the O'Farrell Government to renegotiate the deal that allowed the federal government to publish the results online.
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