Photograph: The practice of "setting" has spread rapidly.
Children at schools in England are being separated by ability from the age of four, according to a report from the school inspection agency.
The document from the Office for Standards in Education (Ofsted) says the use of "setting" has spread rapidly through primary schools in recent years and is helping to raise standards.
The report reveals that setting - as opposed to "streaming" - is being used by around 70% of junior schools and 28% of infant schools.
Setting, most commonly used in English and maths lessons, involves pupils being divided by ability for individual subjects. Pupils could be in the top group for one subject but in the bottom for the other.
Streaming means putting a child in the same ability group for every subject.
The report finds that very few schools avoid setting because of ideological objections - and about a quarter of schools not setting at present expressed their intention to do so in the near future.
"Setting is regarded by most head teachers as a way of catering for the needs of all pupils; it is seen as a means of challenging the most able ... as well as a way of providing smaller, more focused teaching groups for the least able," it says.
"A very large proportion of the schools inspected demonstrated a clear trend of rising standards for pupils of all abilities.
"All but a handful of the schools visited achieved higher scores in national tests in setted subjects in 1997 than in 1996, in some cases spectacularly so and usually by more than the average gains made nationally."
Ofsted's Chief Inspector Chris Woodhead said: "Some of the schools we went into that are setting are achieving spectacular improvements in their children's attainments."
The School Standards Minister, Estelle Morris, welcomed the report. "It shows that setting can make a significant contribution to raising standards and to the successful implementation of our numeracy and literacy strategies," she said.
The General Secretary of the National Association of Head Teachers, David Hart, said: "I am not in the least surprised that there has been a substantial increase in setting in primary schools.
"This is something schools have introduced themselves, as a response to the demand for higher standards. They haven't been led by government initiatives or policy."
**************************************************** * Jerry P. Becker Dept. of Curriculum & Instruction Southern Illinois University Carbondale, IL 62901-4610 USA Fax: (618)453-4244 Phone: (618)453-4241 (office) E-mail: email@example.com