A new study by the Institute of Education looks likely to prove controversial, after it concluded that pupils who are supported by teaching assistants do no better than those who are left alone. Although more positive findings from the research suggested that support staff have had a positive impact on teachers' job satisfaction and stress levels.
The full title of the report is Deployment and Impact of Support Staff in Schools. The full version (166 pages!) of the report is available here, or you can read a more managable summary by clicking here.