It was one of the flagship policies of the fledgling Welsh Government, hailed by former first minister Rhodri Morgan as the "most momentous change to education in Wales since devolution". Launched in 2008, the foundation phase was a radical departure from traditional classroom practice, delaying formal learning until key stage 2 in favour of a play-led approach. And it stood in marked contrast to England's early-years framework, slated by critics for its "tick-box culture".
But despite #163;170 million being spent on the curriculum for three to seven-year-olds, two reports published this month by Estyn, the Welsh schools inspectorate, have raised serious concerns about its impact.
Although inspectors said the foundation phase had helped pupil well-being, and that five to six-year-olds are achieving well, too many schools still did not understand the principles of the scheme and what they should be doing, they warned.
The problem, according to Estyn, is that some staff are not convinced about the educational value of play-led learning and have not implemented it properly. This is having a serious impact on literacy standards. In a number of cases, schools have used the introduction of play-based learning to abandon formal literacy teaching altogether.
"In a significant minority of schools, there is not enough direct teaching of reading, and appropriate opportunities for children to practise and use their reading skills are not always provided," the inspectorate said. Nor were teachers as creative as they could be: "While the foundation phase in nearly all schools provides rich contexts and motivating opportunities for writing, the range and quality of children's written work in many schools is often limited because writing tasks are formulaic and undemanding."
What can be done? Having a clear understanding of what the foundation phase is as well as effective planning and regular assessment are "vital" if it is to succeed, says Estyn chief inspector Ann Keane. "In the best schools, teachers and practitioners have developed challenging and creative activities aimed at developing children's reading and writing skills," she pointed out. "They have high expectations and maintain a strong focus on raising standards of literacy."
Alarm bells first started to ring in Wales earlier this year when some primary heads began to report an unexpected drop in literacy rates and a higher percentage of pupils falling behind their expected reading age.
A senior Welsh Government source admitted at the time that some teachers in the primary sector needed to better understand what the scheme was all about, particularly regarding literacy. "They mistakenly think it's all about play, that you don't do any formal literacy work until KS2, and that's a fallacy," the source said. "We've got to make sure we get the balance right."
Welsh education minister Leighton Andrews is clearly concerned. He has outlined a raft of initiatives to drive up standards - among them, the introduction of annual reading tests for all five to 15-year-olds to make sure pupils are making sufficient progress. But the foundation phase remains popular with heads.
Anna Brychan, director of heads' union NAHT Cymru, said she was surprised that some staff in Wales were sceptical. "There has been some concern expressed by our members that the training hasn't always been as good as it might be, and if that's showing in the lack of understanding of the principles then it needs to be looked at urgently," she said.
"However, the overwhelmingly positive response of parents and pupils will play a large part in breaking down any remaining scepticism."
For the moment, the Welsh Government, too, is supportive. A spokeswoman said it was "encouraging" that Estyn had found the foundation phase was having a positive impact on pupil well-being. But she added: "It is a concern that Estyn has identified a minority of schools where children are not being offered challenging enough opportunities to develop and practise their reading and writing skills. This is clearly not acceptable. We have repeatedly made clear that the foundation phase's concept of learning by doing should not in any way lead to a relaxation in standards, especially literacy. The minister has been very frank about the need for standards in Wales to improve and has made literacy and numeracy a priority."
The first real test of the success of the foundation phase will come next September, when the first full cohort of pupils moves into KS2. How they adapt to a more formal educational setting after years of play-based learning could provide the best evidence yet of the scheme's effectiveness.
The Scheme in Numbers
Source: Welsh Government
#163;170m - Total cost of implementing the foundation phase so far
1:8 - Recommended (but not statutory) adult-pupil ratio for three to five-year-olds (1:15 for five to seven-year-olds)
3,600 - Additional classroom assistants joining the foundation phase workforce since September 2008.