A report into Canberra's public education system has found that the territory's schools perform worse than similar schools in other states despite the ACT's per student funding being among the highest in the country.
Auditor-General Maxine Cooper's report, released Wednesday, also called into question the territory's model of giving schools autonomy.
"This appears to have resulted in a high level of variability in the use of student performance information and management information systems and a wide range of school-based assessment tools used across ACT public schools; for a small jurisdiction such as the ACT this is excessive," Dr Cooper wrote.
ACT government expenditure on public school students is proportionally among the highest in Australia with recurrent expenditure per student of $20,532 in 2014-15 compared to the Australian average of $16,670.
The report notes that ACT public schools perform generally well in NAPLAN but have "comparatively low" participation rates which may distort the accuracy of the territory's results.
As well, a comparison of public schools' 2015 NAPLAN results with similar schools in Australia found the majority of ACT government schools' results were lower than those with a comparable level of socio-educational disadvantage.
In most tests across Year 5, 7 and 9 the gap was more pronounced for ACT public schools with a lower Index of Community and Socio‐educational Advantage value than for those who scored higher on the scale.
Among the report's seven recommendations is the suggestion the Education Directorate examines the guidance and support it provides to schools.
"The Education Directorate should examine what may be the appropriate level of support for school principals with respect to the use of student performance information to drive school improvement and determine how this is to be provided," the report said.
"This should recognise the balance between school autonomy and accountability and central oversight and support from the Education Support Office."
Education Minister Yvette Berry welcomed the report but said the recommendations would be examined "at a later date".
She pointed to the government's Future of Education community conversation as evidence of her efforts to address inequity.
"A lot of the information that's been provided in the report we generally know about and we've been working to improve, particularly around using the NAPLAN data and acknowledging that is a moment in time and it is only one tool that can be used," Ms Berry said
Education Directorate Director-General Natalie Howson said the public system was already "on a school improvement journey".
"We're particularly investing in the quality of our teachers, so at the end of the day the relationship and the interaction between a teacher and their student makes all the difference and if we're going to focus on not just achievement but on gain in learning that's a particularly important aspect of our improvement program," she said.
"There's a myriad of data that can inform both schools and teachers about the progress of learning in the student and we're putting that information into a more useable format and ... giving them access to training so they know how to use that data effectively."
Also in Dr Cooper's report were findings by Victoria University education researcher Stephen Lamb.
Professor Lamb examined ACT public schools' educational performance, as measured by NAPLAN, with reference to socio‐educational advantages.
He found the ACT was the worst of any jurisdiction in Year 5 numeracy mean scores. Students were performing 20 points lower than comparable students in another jurisdiction, representing an almost six month gap.
In Year 9 the numeracy deficit jumped almost 25 mean score points.