Because the law does not clearly state to what degree the least restrictive environment is, courts have had to interpret the LRE principle. In a landmark case interpreting IDEA's predecessor statute (EHA), Daniel R.R. v. State Board of Education (1989), it was determined that students with disabilities have a right to be included in both academic and extracurricular programs of general education. But, the Court stated, IDEA does not contemplate an all-or-nothing educational system in which children with disabilities attend either regular or special education. Rather, the Act and its regulations require schools to offer a continuum of services. Thus, the school must take intermediate steps where appropriate, such as placing the child in regular education for some academic classes and in special education for others, mainstreaming the child for nonacademic classes only, or providing interaction with non-disabled children during lunch and recess. The appropriate mix will vary from child to child and, it may be hoped, from school year to school year as the child develops. If the school officials have provided the maximum appropriate exposure to non-disabled students, they have fulfilled their obligation under IDEA.
In Board of Education, Sacramento City Unified School District v. Rachel H., 14 F.3d 1398 (9th Cir. 1994), four factors were identified as things needed to be taken into consideration when determining if the student's LRE is appropriate. They are:
-the educational benefits of integrated settings versus segregated settings,
-nonacademic benefits (primarily social interaction with non-disabled peers),
-the effect the student with a disability can have on the teacher and his or her peers, and
-the cost of supplementary services that will be required for that student to stay in the integrated setting.
Simply stated, the student should receive an appropriate version of the educational and social benefits which non-disabled students routinely receive in school. In broad theory, the court does not allow the education of the student's non-disabled peers to be negatively affected, although applying this test fairly to all the facts and circumstances of a specific situation may be very difficult. The final factor, cost of supplementary services, provides a safeguard for schools so that they do not exceed spending on one particular student.