Researchers behind another damning report into the ACT's education system have called for a public inquiry into why Canberra government schools underperform compared to their counterparts interstate.
Progressive think-tank The Australia Institute will on Friday release analysis of NAPLAN data that shows the majority of high socioeconomic public and private primary schools record worse results than comparable schools outside the ACT.
The report was given to the ACT government in 2015 and made public this week out of frustration by researchers "flabbergasted" by how badly well-off Canberra schools fared.
The ACT consistently tops the nation in NAPLAN testing, but the Australia Institute research found 70 per cent of primary schools' results were below the corresponding mean of schools with similar socioeconomic profiles. In 41 per cent of cases, they were significantly or substantially below.
The results of non-government schools have deteriorated over time but, overall, public schools performed worse than private schools.
The Australia Institute's Andrew Macintosh said the ACT government's ongoing Future of Education community conversation wasn't enough.
"Given that things are getting worse I think there's a desperate need for a public, detailed inquiry to find out exactly what is going on," Professor Macintosh said.
"I don't think it's in any way, shape or form good enough to turn it over to the community. We need experts to spend a good amount of time finding out what is going on in our schools and trying to find the answers to explain why we're seeing the results that we're seeing."
Education Minister Yvette Berry said the government would draw on expert advice when forming a strategy based on the issues raised during the Future of Education talks.
"The Auditor-General has already addressed the issues in the Australia Institute's report and the government is considering the recommendations the audit report made," she said.
"This report addresses the same period as previous reports on data and performance and draws the same conclusions.
"The government is already well advanced in work across ACT schools to improve student achievement, use of data and the outcomes that flow from effective data use."
The Australia Institute has suggested two possible explanations for poor results in the public system: that the socioeconomic scores used by the Australian Curriculum and Reporting Authority may not capture the true profile of the ACT, making the comparisons inaccurate, or that teaching practices were to blame.
Among the recommendations is the implementation of direct instruction teaching methods via a voluntary program in underperforming schools.
"We don't think the trial will provide any new evidence that'll show that direct instruction is more effective than other methods because we think that evidence is already out there," Professor Macintosh said.
"The purpose of the trial is really to show to Canberra teachers that direct instruction works and is not talking about reverting back to the 1960s nor is it talking about necessarily using commercial products that cost you hundreds of thousands of dollars a year."
The Australia Institute's findings were based on the results of 18 government and six non-government primary schools out of a possible 100. The schools studied were among the nation's top 10 per cent as measured by socioeconomic status.
Last month, Education Directorate director-general Natalie Howson said no research had been done on why Canberra's Indigenous students were an average of two years behind their peers.