The impact of the 10 projects within the Assessment is for Learning (AifL) programme varies "with project and across sectors and authorities", researchers from Strathclyde University's Quality in Education Centre say.
About one in four teachers said they had evidence of improved attainment, but the majority thought it was too early to say.
Four years on, most of the classroom focus has been on formative assessment, the first of the 10 projects, followed by trials with personal learning plans.
In their final evaluation, released today (Friday), Rae Condie, Liz Seagraves and Kay Livingston report that most teachers and heads say it is too early to judge the overall impact, although in some schools and authorities "involvement in the programme had begun to change practice".
The programme combines top-down and bottom-up development, using projects that cover aspects of formative and summative assessment, recording and reporting.
In interviews following the second phase of the programme between 2003 and 2004, two-thirds of heads in the pilot schools thought it had substantially influenced development planning, though primary heads were more of this view than secondary colleagues. It was encouraging them to develop or revise school assessment policies.
Both teachers and heads agree that there was increased awareness of research, clearer understanding of assessment, changes to classroom practice, more varied approaches to assessment, and more meaningful discussion with pupils about their learning.
But the researchers, commissioned by the Scottish Executive, add: "The greatest challenges to introducing change were time and engaging all staff.
Time was at a premium both for preparing materials and engaging in dialogue with colleagues, due to competing priorities and also, in some cases, lack of supply cover.
"Agreement that there was resistance to new developments and difficulty in changing practice had increased since the first survey (in 2003).
Maintaining enthusiasm and engaging new staff was more challenging as the programme progressed."
The researchers believe a major strength is the central role given to teachers to develop alternatives on assessment and to engage in classroom research. "This had led to high levels of commitment and enthusiasm," they state.
Funding was also key with half of heads saying they would never have tried any of the developments without it. Most of the cash went on supply cover or paying teachers for work in their own time.
Other important factors are said to be the supportive networks (involving other schools and local authority staff), extensive staff development and expert input.
"Small-scale research projects engage teachers, giving them a sense of ownership and control over developments and the management of change.
Significant change occurred in schools and authorities that embraced the opportunities offered," the Strathclyde team says.
But the style of the programme risks fragmentation because of the variety and spread of projects. The team concludes: "This is just a beginning, albeit a positive one. However, it may be necessary for the Scottish Executive to maintain a high profile for AifL, through national and regional events and ongoing publicity."
Evaluation of the Assessment is for Learning Programme: Final Report 2005.
By Dr Rae Condie, Dr Kay Livingston and Liz Seagraves of the Quality in Education Centre at Strathclyde University. The report is on the Scottish Executive website.
TEN ON TRIAL
Formative assessment, personal learning plans (PLPs), support for managing PLPs, gathering and interpreting assessment evidence, local moderation, new National Assessments, Assessment of Achievement Programme, ICT support for assessment, reporting to parents and others, meeting the needs of pupils with additional support needs.