"All affected schools have been contacted and any wishing to re-sit tests have been instructed to opt-in by midday Tuesday 21 May and inform NESA which students will be re-sitting tests by 4pm Wednesday 22 May," the spokesman said. "Only students who experienced disruption on Tuesday 14 May, preventing them from having a fair opportunity to demonstrate their ability, will have the option to re-sit that particular test. Loading "Participation in re-sitting tests is entirely optional and parents or schools can opt not to re-sit any of the tests in which students were disrupted by the connectivity issues experienced last Tuesday." The Australian Curriculum, Assessment and Reporting Authority, which is responsible for the tests, has repeatedly said that technical glitches only affected Tuesday's tests.

However NSW Education Minister Sarah Mitchell said the problems continued on Wednesday and Thursday, and more than 400 schools were affected by the end of the week. Hundreds of schools in Victoria and Western Australia were impacted by glitches. Head of the NSW Secondary Principals' Council, Chris Presland, also confirmed that primary and high school students experienced problems during online tests throughout the week and not just on Tuesday. "There's no doubt about that, we heard from high schools and primary schools, they reported intermittent drop-outs on Wednesday and Thursday," Mr Presland said. Mr Presland said the range of variables now involved in this year's NAPLAN testing will make it impossible to get any valid data from the results.

"Statisticians can say all they like that they can compare results from different tests but that doesn't take into account human factors," Mr Presland said. Loading "You now have students who sat it the first time and experienced problems and got completely stressed and will not decide to do NAPLAN two, you'll have students who had problems and will do NAPLAN two, you have students who didn't experience problems the first time, you have students who sat the tests on paper. "The number of variables is now just ridiculous, the information any teacher or system can gain from this test ... it's just completely polluted." Travis Fuller, whose daughter is in year 5 at a public school on Sydney's northern beaches, said she reported experiencing technical glitches on Wednesday and Thursday as well. He said he would most likely opt for her to re-sit the exam next week.