More than one million students sat for the tests on Tuesday with one in five swapping pencils for computers for the first time.

NAPLAN tests the reading, writing and maths abilities of children in Years Three, Five, Seven and Nine, providing valuable information to improve education across the country.

Senator Birmingham's NSW counterpart Rob Stokes says the tests are being misused as a school rating system and an "edu-business" industry has sprung up around it to extort money out of worried parents.

The Australian Education Union says NAPLAN provides a "narrow and incomplete picture" of a student's education and should only be treated as a snapshot.

The Australian Curriculum, Assessment and Reporting Authority said parents need to remind their children it is "not a big deal", but rather a short assessment taken only four times during their schooling.

The federal government is considering terms of reference for a possible review of NAPLAN.

However, Senator Birmingham, who visited a research facility in Adelaide on Tuesday, said NAPLAN was "here for the long-term".

"In terms of NAPLAN, as we stand here, in a world-class research facility, you don't get world-class researchers without them first having the fundamental basics of literacy and numeracy," he said.

"It's important for policymakers to track where our education system is heading, and identify those who are getting the best possible outcomes."

He said he would receive a report on how well the online system worked and any problems which needed addressing.

Australian Associated Press