A high-profile, Government-funded programme designed to help pupils develop their thinking and assessment skills has failed to have an impact on classroom standards, according to a new report.
Schools watchdog Estyn says there is little evidence that the Developing Thinking Skills and Assessment for Learning programme has led to improved test results for seven, 11 and 14-year-olds.
More than 870 teachers have taken part in the scheme since 2005. It aims to improve pupil performance, increase their engagement with learning, change classroom practice, and increase the amount of creative lessons on offer.
But chief inspector Ann Keane said: "It is very difficult to attribute improvements in pupils' performance specifically to the impact of this programme.
"Evidence shows that the programme has succeeded in boosting many teachers' and pupils' confidence. We have seen better lesson planning to develop pupils' thinking skills, with teachers using a wider range of teaching styles.
"But to be fully effective, the programme's techniques need to be applied in the context of a curriculum that is designed to develop pupils' skills progressively."
The report says there is still too much variation in the quality of teaching within and between schools.
Not all lessons observed by inspectors demonstrated assessment for learning or thinking skills in a meaningful way, and practice in most secondaries was less developed than in primaries.
Back in 2008, an independent evaluation of the programme found no significant impact on attainment, and said it was likely to take several more years.
But Estyn says not enough has been done by schools, local authorities or the Government to evaluate the impact of the programme on pupil standards, well-being or attitudes towards learning.
The programme lacks clear expectations about its planned impact and does not provide enough guidance on evaluation, the watchdog says.
The report makes a number of recommendations, including that the Government should establish clear success criteria for the programme so its impact on standards and value for money can be properly evaluated.
The Government said it noted Estyn's comments on the need for more evidence, but added it was pleased that the inspectorate noted improvements to pupil attitudes to learning and changes to teaching practice.
A spokeswoman said: "Although it is always difficult to isolate the impact of one initiative on pupil outcomes, we have already put in place plans to provide additional support for local authority advisers in working with schools to assess the impact of the programme."