Teachers in Wales already know they have their work cut out if they are to help the country improve its standings in international education league tables.
It is education minister Leighton Andrews' ambition for Wales to be among the top 20 leading nations in the 2015 Programme for International Student Assessment (Pisa) tests.
But out of 67 countries taking part in the 2009 tests, Wales was ranked 38th for reading, 40th for maths and 30th for science. England was 27th, 28th and 16th respectively.
Last week, the minister set out for the first time exactly what bettering these standings would mean in terms of improved performance, and the scale of the task ahead is staggering.
If Wales is to achieve Mr Andrews' Pisa goal, then the number of pupils achieving the Level 2 threshold of five good GCSEs (grades A*-C) - including maths and either English or first-language Welsh - must increase from 50.5 per cent to 65 per cent in the next three years, he said.
To put that into perspective, in the five years since the Welsh government started collecting figures, the number of 15-year-olds achieving the measure has only increased by 6.1 per cent, up from 44.4 per cent in 200607 to 50.5 per cent in 201112.
In that time, the highest year-on-year increase was 2.2 percentage points, between 200809 and 200910, and since then growth has slowed; this year's results were up just 0.4 percentage points on 201011.
Speaking to TES, Mr Andrews admitted that the aim was "challenging", but said it could be achieved with the efforts of everyone in the education system. "We believe that now, through the work of the regional consortia, there's a much clearer focus on what needs to be done, year-on-year, to get there," he said. "I have spelt out in no uncertain terms what needs to be achieved if we want to hit that Pisa target."
But some educationalists are not as certain. Gareth Jones, secretary of heads' union ASCL Cymru, said: "I don't think it's realistic as a target, but I have no problem with it as an aspiration. The clear message is if we are to close the gap that's the kind of performance we need to hit."
David Reynolds, a senior policy adviser to the Welsh government, said: "There's no doubt that this appears to be a big ask because our performance in GCSEs has plateaued in the past couple of years.
"On the other hand, the fact that a number of policies and plans will be working their way through the system in the next three years suggests things should pick up."
Mr Andrews set the new target while launching an implementation plan that sets out the course of Welsh education reform in the coming years. Since announcing a 20-point action plan to improve educational standards 18 months ago in the wake of Wales' "disastrous" performance in the 2009 Pisa tests, Mr Andrews has focused on three key aims: improving literacy and numeracy and reducing the impact of poverty on attainment.
There have been a number of developments to support this. At one of the system, the Department for Education and Skills has become more focused, with a new school standards unit set up to drive improvement, while Wales' 22 local authorities have been brought together in four regional education consortia to support and challenge schools.
Other measures include new literacy and numeracy frameworks, which place an expectation on all teachers to teach literacy and numeracy across the curriculum, and the opportunity for newly qualified teachers to improve their skills by studying a newly-created master's in educational practice qualification.
What lies ahead
Upcoming developments in Wales' education system include:
First set of Pisa Inset materials published.
Review of initial teacher training launched.
Regulations introduced for mandatory training of school governors.
Secondary school banding positions revealed.
DfES starts to work with regional consortia to test "readiness".