The literature review of educational provision for pupils with additional support needs found that, worldwide, boys appear to have more difficulties in coping with mainstream education than girls and attract a greater proportion of additional resources.
However, the report, published by the Scottish Executive with the universities of Edinburgh and Glasgow, revealed radically different approaches to special needs across the five case-study countries - England, the United States, Greece, Sweden and the Flemish community in Belgium.
While the US, England and Sweden run multi-track systems, Greece is much closer to a one-track system with very little investment in its special sector, and Flanders has a two-track system with strong insulation between special and mainstream schools, including separate curricula.
The paper reports on a backlash against inclusion in England and Sweden, where the trend is to delegate funding to schools, thus making the connection between additional funding and the needs of individual pupils less clear-cut.
"If parents believe that children will only receive additional resourcing in special settings, then they may regard such placements as preferable to mainstream schools, where they may struggle for additional resources."
The authors acknowledge that mainstream schools which are measured by league tables are not enthusiastic about inclusion, as including SEN children in league tables can affect the school's position. Nevertheless, the report reveals an international move away from categorising by medical needs and towards inclusion.
"Most countries appear to favour eclectic forms of provision, with parallel developments in inclusive education, special classes or units in mainstream schools and special schools."
The researchers report that in Scotland, while individual educational programmes (IEPs) are generally regarded as the vehicle for specifying targets for pupils with additional support needs, there have been problems in their implementation. These include a possible narrowing of the curriculum, a lack of ownership by secondary subject teachers, and low levels of involvement by parents, pupils and external agencies.
A Curriculum for Excellence appears to offer possibilities for the further development of more flexible programmes, as opposed to alternative programmes, for pupils with support needs, it says.
"Standard grade is regarded as too difficult for some pupils with SEN, particularly those with significant difficulties with literacy and numeracy. Some pupils with SEN follow Access courses which form part of the Higher Still programme. However, some mainstream teachers find it difficult to teach pupils studying Standard grade and Access courses in the same class because of differences in course content."
The researchers interviewed international experts from the UK, the US, Belgium (Flanders), Sweden and Greece about policy and statistics in their own countries. In all cases, the researchers found a trend towards inclusion.
But they added: "There was no clear view emerging from the literature as to whether mainstream or special education provided more positive outcomes for pupils.
"The lack of good evidence here is attributable to the difficulties in gathering comparable data about the outcomes of schooling for pupils with SEN."