Pisa is an international standardised assessment for 15-year-olds Test results comparing Welsh pupils with the rest of the world are expected to be a “disaster”.
BBC Wales understands the assembly government is preparing for another poor performance in the Pisa assessments.
They test up to 10,000 15-year-olds in each of 65 countries in reading, maths, science and problem solving.
The assembly government would not comment until the results are formally released.
But sources close to the assembly government say the publication of the results on Tuesday will be a “reality check”.
The Programme for International Student Assessment (Pisa) performance tables are carried out every three years and grade teenagers against their peers in other countries.
“”The results must be put in the context of the funding gap between Wales and England”
Rex Phillips NASUWT Cymru
In the last set of results conducted in 2006 and published in 2007, Wales performed the worst of the UK nations.
Although Welsh students performed well on science, the report revealed below-average performances in reading and maths, comparable to eastern European countries such as Croatia and Azerbaijan.
The BBC has been told that assembly government officials are working on the assumption the results will be a “disaster”.
Wales will be under scrutiny to close the gap with the rest of the UK after last time.
After the last set of results the assembly government’s aim would have been to close the gap on Scotland, Northern Ireland and England.
Rex Phillips, Wales organiser of the NASUWT, said the results should not be used as a “stick to beat teachers with”.
He added: “The (education) minister should avoid knee-jerk reactions and work with the teaching profession, not against it.
“The results must be put in the context of the funding gap between Wales and England.”
A Welsh Assembly Government spokesman said they would not be commenting until the confidential results are released.
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