A more thorough explanation:

Mainstreaming is a term used in education to describe the practice of including students with disabilities in regular classrooms to the greatest extent possible. This is required by the Individuals with Disabilities Education Act (IDEA), which mandates that children with disabilities should be educated with children who are not disabled, as long as it is appropriate.

For example, if a child with a disability can learn effectively in a regular classroom with the help of special aids and services, then they should be included in that classroom. However, if the child's disability is too severe to be accommodated in a regular classroom, then they may need to be placed in a separate classroom or school.

There are different approaches to determining whether a child's educational plan is appropriate. For example, the Daniel R.R. test looks at whether education in a regular classroom with supplemental aids and services can be achieved satisfactorily for a given child, and if not, whether the school has mainstreamed the child to the maximum extent appropriate. The Roncker test looks at whether the services that make a segregated placement superior could be feasibly provided in a non-segregated setting.

Overall, the goal of mainstreaming is to provide children with disabilities with the same educational opportunities as their non-disabled peers, while also ensuring that their individual needs are met.