Poor Australian students are about three years behind in their schooling compared with their richer peers.
A new analysis of results from two international maths and science tests finds the gap between advantaged and disadvantaged students has barely narrowed over the past 15 years.
Education Minister Simon Birmingham, who is in the midst of negotiating a new school funding deal with the states and territories, says the warning signs in the results make it clear money has to be spread around properly based on need.
The analysis shows socio-economic factors, teachers and school environments make a big difference to student achievement.
The decline in the achievement of poorer students was especially worrying, the Australian Council for Educational Research's Sue Thomson said.
"It also matters which school a student attends," Dr Thomson said.
Her analysis found disadvantaged students in average schools were almost a year ahead in academic achievement compared with similar children in poorer schools.
And poorer students who attended advantaged schools were another year ahead again.
Dr Thomson also told SBS that 20 per cent of Year 4 students are bullied regularly.
"So the one of the main findings was that the gap between advantaged and disadvantaged students is large, it's about three years of schooling in all subject areas. And it hasn't changed in the last 15 years.”
Disadvantaged students were less likely to describe most of their teachers as very engaging or supportive - but when they did find those excellent teachers they flourished.
The assessments also found:
* One in five Year 4 students and one in 10 Year 8 students reported being bullied almost weekly - and did worse in school as a result.
* About one-third of students in richer schools and half those in poorer schools said most classes were noisy or disorderly and they found it difficult to learn.
* About two-thirds of maths teachers had trained in that subject.
* One in three principals of disadvantaged schools said inadequate infrastructure hindered their teaching capacity - compared with one in eight principals from advantaged schools.
The Australian Education Union highlighted findings that on every measure students at disadvantaged schools were more likely to be hurt by staff shortages, with the biggest issues in the Northern Territory, followed by Tasmania and Queensland.
Senator Birmingham said Australia stacked up well compared with many countries but the warning signs were clear.
"This research demonstrates that more money spent within a school doesn't automatically buy you better discipline, engagement or ambition," he said.
"While well-resourced schools with highly capable and motivated teachers are central to success, we equally need policies and parents that empower teachers to expect high standards and adopt a zero tolerance approach to bad behaviour."
The two tests - TIMSS, assessing Year 4 and 8 maths and science, and PISA, examining 15-year-olds - were done in 2015. Their preliminary results were reported late last year.
Principal of St Andrews Cathedral School in Sydney, Dr John Collier, says his teachers are adapting new strategies to keep their classes relevant and interesting.
"We need to keep their attention. And initially keeping (the) students' attention and stimulating them with the joy of learning and the processes of learning is vital to actually have them achieve. And so we've built technology platforms into our teaching methodology, as we've endeavoured to be 21st century learning in our approach and as we've adapted to the way young people have changed.
"(The) most important part is a strong sense of belonging and purpose in what they're doing, so that it makes sense and they can see that it matters."
- SBS News with AAP