The Individuals With Disabilities Education Act, or IDEA, addresses how states and agencies supply services to individuals with disabilities. This act requires states to educate all students with disabilities. Much of the funding for this education comes from IDEA, provided that school districts are complying with IDEA's principles. Inclusion education largely grew out of Part B of IDEA, which addresses the education of people ages 3 to 21.
One of the six principles laid out by IDEA states that children with disabilities must be educated in the least restrictive environment available -- preferably an environment with non-disabled peers in a "typical" education setting. In the past, the majority of students with disabilities were educated in self-contained settings -- classrooms made up of a special education teacher and several disabled students and their instructional aides. In order to determine the least restrictive environment for a particular student, schools will often start the student in a general education classroom and, if the student is not successful, begin to move the student to more restrictive environments.
Partial Inclusion describes inclusion settings where a child with disabilities spends part of the school day with non-disabled peers in a general education setting and part of the school day in a self-contained classroom or resource room or working with a teacher or specialist on a one-to-one basis. For students with severe learning and developmental delays, it is common for their inclusion to take place during classes like art, music, gym and dance and for the student to remain separated for core curriculum classes like language arts, math, science and history. It is also possible for a student to attend some or all core classes in a general education setting and be pulled out during enrichment periods.
Full inclusion describes an inclusion setting where students with disabilities and general education students spend the entire day together as a class unit. A full inclusion class is often co-taught by a general education teacher and a special education teacher, with both teachers sharing equal responsibility for the entire class. Lessons are differentiated for all students and little to no distinction is made between disabled students and their non-disabled peers. Students with disabilities might have additional aides in the classroom or might be pulled out for short periods of the day for resource, remedial or therapeutic services. It is also possible for disabled students to be mainstreamed into a general education classroom with only an aide or pull-out services.