Australia's education minister is embarrassed by the "appalling results" of the nation's students in the latest international maths and science tests, which have seen them drop behind countries such as Kazakhstan.
The 2015 results from the Trends in International Mathematics and Science Study (TIMSS) shows Australian students are still middle of the pack after 20 years of testing.
But they've slipped down the rankings, beaten by students in Kazakhstan and Slovenia.
"I think they're appalling results," Education Minister Simon Birmingham told ABC radio on Wednesday.
"I am embarrassed for Australia that we are not performing at the standard that we would expect our schools to perform."
The 2014 TIMSS tests looked at how well year 4 and year 8 students have mastered maths and science lessons, asking questions like how many legs an insect has and what the angles in a triangle add up to.
The results showed that since 2011 Australian students have:
* Slipped 10 places in rankings for year 4 maths (18th to 28th)
* Made no progress in year 4 science (steady at 25th)
* Dropped five places for year 8 maths (12th to 17th) and science (12th to 17th).
The Australian Council for Educational Research, which reports on the four-yearly study, says a particular concern is that between a quarter and a third of Australian students are still not meeting the proficient standard.
The council's Sue Thomson highlighted the huge role socio-economic background - measured by the number of books at home - played in a student's success.
If just the results from the richest students were used, they would be among the top eight countries in the world, whereas those from poorer families are within the bottom quarter.
"I'm not necessarily going to relate it to funding, however we're back at the table insofar as school funding goes and we're still finding that disadvantaged students from disadvantaged schools are those who are not achieving well in these sort of tests," Dr Thomson told AAP.
"They're the ones we need to be targeting to try and improve their achievement."
Senator Birmingham intends using the results in discussions with state ministers about a new schools funding system but says the conversations shouldn't inevitably turn to more money.
It needed to be about how to use record levels of funding more effectively.