Ireland has slipped down the OECD education rankings in literacy and maths, in a move which could damage the strong international standing of the Irish educational system.
On reading levels, Ireland has slipped from 5th place in 2000 to 17th place, the sharpest decline among 39 countries surveyed.
In maths, Ireland has fallen from 16th to 26th place, the second steepest decline among participating countries. Ireland is now ranked as below average in maths.
Yesterday, the Department said the increase in migrant children, the greater inclusion of children with special needs and fewer early school leavers could explain the decline in literacy and maths standards. But the Department acknowledged these factors might explain some but not all of the latest findings.
Minister for Education, Mary Coughlan said she was disappointed with the findings.
The key findings of the OECD/PISA survey for Ireland include:
Reading
* Between 2000 and 2009, Ireland has fallen from 5th place amongst 39 countries to 17th place.
* This fall is the worst of all countries.
* One in six students in Ireland are estimated to have poor reading skills – 17 per cent are low achievers in reading.
* Almost a quarter of males (23 per cent) achieved an average score which is considered to be below the level of literacy needed to participate effectively in society.
Maths
* Ireland has fallen from 16th place to 26th place in just three years between 2006 and 2009.
* This fall is the second largest of all countries.
* Ireland has significantly fewer students attaining higher proficiency levels than the OECD average: 6.7 per cent compared to 12.7 per cent.
Science
* There has been no change in science achievement since 2006 .
The Irish National Teachers' Organisation said test results for Irish pupils in PISA 2009 should be treated with caution particularly comparisons between PISA 2009 and PISA 2000.
"It is important not to read too much into a single test," said Into general secretary Sheila Nunan.
"All other evidence shows that Irish literacy and numeracy standards are stable.
The Into said evidence from national assessments of English or Mathematics, carried out every five years, shows that the performance of primary-level students in Ireland has stayed the same. In the case of reading, no significant changes in average performance at fifth class level have been recorded since 1980.
The union said it was important to note that experts from the Educational Research Centre concluded that changes in the curriculum at primary level cannot explain the decline in performance on PISA reading literacy between 2000 and 2009.
The Into said significant changes over the past decade could not be ignored. "In almost every Irish classroom there are more pupils who do not speak English as their first language and more special needs pupils," said Ms Nunan. "Nor have class sizes been reduced to allow teachers to teach this different cohort of children and to implement the curriculum as intended."