Speaking before an ACT inquiry into standardised testing this week, Wanniassa School principal Shane Gorman said he was tempted to steal the NAPLAN papers when they arrived at the school gate each year as he had witnessed the test's destructive toll on students.

"I feel I’m part of the Stanford prison experiment [where they were told] to give an electric shock to their colleagues," Mr Gorman said.

"I'm forced to go in and do that to my students ... to do things that I know is really bad for them psychologically and I know is really bad for their learning."

In the case of a year 5 student with a mental illness, Mr Gorman said he had even tried to convince the child's parent to withdraw him from the test.

"I could lose my job over that," he said, adding he was "likely to get emotional" while recounting the harm anxiety over the test had wrought on that particular student.

Mr Gorman was flanked by the head of Australian Eduction Union's ACT branch Glenn Fowler, who said there had been suicides in the US as a result of high stakes school rankings.

In Canberra, the majority of teachers surveyed by the union backed growing calls to scrap the test, reporting results arrived too late to be of practical help in classrooms but created undue stress in schools.

"If doctors said, in near unanimity, that a practice did more harm than good for their patients, would they be ignored for nine years?" Mr Fowler asked the committee.

He called for an end to the annual "circus" sparked by the publication of results on the My School website as well as a comprehensive review of the NAPLAN test, as proposed by federal Labor.

"[It] is a dead test walking. It’s past its use by date," Mr Fowler said.

"NAPLAN and My School were done to us, by the former federal Labor government, not with us ... We demand that reform is done with us."

Brett Stanton from the ACT Auditor-General's office said while the NAPLAN participation rate in Canberra was low, particularly for year 9 students, he backed analysis by the Grattan Institute which found NAPLAN was a valuable indicator of academic performance.

A report by the Auditor-General's office released in 2017 warned ACT public schools were lagging behind comparable schools elsewhere despite the high government spending on students.

Also appearing before the inquiry on Tuesday, ACT education minister Yvette Berry said lifting equity in schools was shown to boost school performance across the world, and so had been placed at the centre of the government's new 10-year Future of Education strategy.

Ms Berry, who is currently spearheading a national review into the reporting of NAPLAN results on the My School website, said there was strong scepticism in the sector about the value of the assessment.

As a jurisdiction, the ACT placed a low emphasis on the test compared to some other states, the inquiry heard.

Mark Huxley at the education directorate said the national school improvement tool was a more comprehensive way to measure schools than NAPLAN.

Each year about 18 schools in the ACT were cycled through an independent review process. Data was analysed and targets set as each school developed its own five-year strategic plan, he said.

At the Canberra Montessori School, which offers an alternative education setting almost entirely free from formal testing, principal Anthony Vandermolen said NAPLAN was still something of a "fun" novelty for students.

"With my psychology background, I understand the purpose of standardised testing ... but I don't like that it's being used as a teacher assessment or a school assessment, it really needs to be used for the purpose for which it was designed," Mr Vandermolen told the inquiry.

The inquiry continues.

An earlier version of this article stated Mr Fowler had mentioned suicides due to NAPLAN rankings. He was referring to suicides in US school rankings.