In the battle of the sexes, do Victorian boys outperform girls in the national literacy and numeracy test?

A Fairfax analysis of the latest NAPLAN results for Victorian single-sex secondary schools shows there is not much difference between the performance of Year 9 students.

The federal government's MySchool website was updated on Thursday, providing parents with new details of about 9500 Australian school's literacy and numeracy performances, demographics, finances and attendance rates.

Among non-government boys schools, the average score for reading at Year 9 level was 608, compared with 622 for girls-only schools.

And in Year 9 maths, the average score at girls schools was 619, compared with 632 for the boys.

This might seem like a sizeable gap, but because of the way the data was collected the differences are not significant enough to reach a solid conclusion.

The analysis revealed independent single-sex schools perform better than the national average in reading and mathematics.

The national average for all schools at Year 9 level is 580 in reading and 588 in numeracy.

Many of the non-government single sex schools are located in Melbourne's wealthy inner suburbs, and attract some of the best and brightest students with scholarship programs, so there's no suggestion that being single-sex is the key to their success.

Jennie Carter, director of learning and teaching at Sacré Coeur in Glen Iris, said students performed better at single-sex schools because they were not held back because of their gender.

The school has made a concerted effort to improve its numeracy performance in recent years which has paid off.  After investing more in professional development for teachers, Year 9 students lifted their average numeracy score from 592 to 632.

She said students had embraced maths and science.

"When we talk about maths and science the girls know it's for them. It's not like in a co-ed school where they might think it's a boys' subject."

Melbourne University education policy lecturer Glenn Savage said a school's achievements were much greater than their NAPLAN results and that parents sent their children to single-sex schools "for a whole range of reasons, and many of these will have nothing to do with test scores".

Meanwhile, a report released by the Australian Curriculum, Assessment and Reporting Authority on Thursday by research firm Colmar Brunton found principals were concerned that parents were misinterpreting NAPLAN results.

The report also revealed that some parents believed certain schools were "coaching" children for NAPLAN and excluding "less able" students from sitting the test, which meant the results may not paint an accurate picture of a school's situation.

The analysis is based on NAPLAN results of 66 non-government Victorian single-sex schools, which were published on the My School website. Of these, 22 were boys' schools and 44 were girls' schools.

Schools that have separate campuses for girls and boys, such as Ilim College or Haileybury, were not included in Fairfax Media's analysis due to the way My School presents the data.