SYDNEY, Dec 10 - An OECD study has found that many Australian schools have Year 11 and Year 12 students who lack basic necessities such as adequate housing, nutrition and medical care.

The latest OECD Teaching and Learning International Study - the world's largest international survey on teaching and learning - says 66 per cent of Australian upper secondary teachers work in schools where principals report that more than 10 per cent of the students come from so-called "socio-economically disadvantaged homes".

The figure puts Australia above Poland where 62 per cent, almost on par with Mexico where the figure is 70 per cent, and well above the average of 43 per cent among countries surveyed.

In Norway, the figure is just 16 per cent.

"It is important to ensure that teachers in these schools are well equipped so that they can provide students with effective learning environments despite these potentially more challenging school environments that can be linked to having large numbers of students from socio-economically disadvantaged homes," the report found.

The report also says Australia has a significantly low proportion of women employed as principals in upper secondary education despite women being the majority of the teaching workforce.

The TALIS survey also found significantly fewer principals are women at all education levels around the world.

In Australia, while 57 per cent of upper-secondary teachers are women, 39 per cent of principals are female - the lowest proportion among countries surveyed - compared to the average of 46 per cent, and 54 per cent in Singapore.

Secondary school principals said shortages of teachers and support personnel, and particularly a lack of qualified teachers, were key factors affecting quality of education, the report said.

"These conditions are more likely to affect schools with large proportions of disadvantaged students or schools located in rural areas."

The survey also found a marked difference in class sizes at upper secondary education level, with smaller class sizes on average in Australia and Norway (19) compared to 33 in Singapore and 34 in Mexico. 

Proportion of principals reporting more than 10 per cent of students are from socio-economically disadvantaged homes: 

1. Mexico (70 per cent)

2. Australia (66 per cent)

3. Poland (62 per cent)

4. Finland (51 per cent)

5. Singapore (50 per cent)

6. Italy (43 per cent)

7. Denmark (39 per cent)

8. UAE (37 per cent)

9. Iceland (24 per cent)

10. Norway (16 per cent) 

Source: OECD Teaching and Learning in Primary and Upper Secondary Education Report