The testing authority responsible for the NAPLAN assessment for all students in years 3, 5, 7, and 9 across Australia has apologised for any inconvenience caused on Tuesday when "connectivity issues" left thousands of students unable to complete the online test.
"Education Services Australia continues to investigate the cause of connectivity issues experienced by some schools during NAPLAN Online yesterday," the Australian Curriculum, Assessment and Reporting Authority (ACARA) said in a statement.
"Any inconvenience to schools and students during testing is regretted, and if technical issues are experienced in the coming days, there are procedures in place to manage them and ensure that all students are able to take the tests."
Such procedures include taking the test on paper as a last resort.
Meanwhile, Western Australia's education director general Lisa Rodgers is blaming the issue on the NAPLAN national firewall.
"Over 700 schools in WA have been taking NAPLAN Online. We know that nationally there has been an issue with the firewall and lockdown browser, that's been a national problem," she said, speaking on ABC Radio's Drive program in Perth on Tuesday.
"We've had quite a lot of success with the online platform, [however] this year we are getting a number of calls in regards to that browser."
ACARA said the logistics of a project the size of NAPLAN are "highly complex".
"The technology and logistics of a national online project of this size are highly complex, involving national testing authorities, states and territories, and schools, and the cooperation and assistance of all involved is appreciated," ACARA's statement continued.
ACARA CEO David de Carvalho told ABC Radio on Wednesday that the authority is working as hard as it can to address the problem.
"It's unusual because last year we had a very smooth operation and so this is something that still needs to be investigated. It hasn't occurred before in quite the same manner, so we are still working hard to understand the precise cause," he said.
With Victoria flagged as one of the states most affected by the glitch, Minister for Education James Merlino told media an apology from ACARA wasn't good enough.
"Frankly I'm so fed up with ACARA, I'm not much interested in what they've said, they've gone out and said, 'it's regrettable that this has occurred' -- it's not regrettable, it's simply not good enough," he said.
"We were given assurances by the federal government and the national bodies that they've worked through all of the issues with NAPLAN online and that it would work. It simply did not."
The testing is run over a two-week period.