It was during this period that the term mainstreaming became popular. Over the years, because mainstreaming has been used in many contradictory and incompatible ways, it is difficult to know what was actually meant by the phrase at any given time. Often, however, "mainstreaming" meant placement in regular classes with little support.
When the Individuals with Disabilities Education Act (IDEA) was implemented in the 1977-1978 school year and until sometime in the mid-1980s, the term that described the education of students with disabilities with those who did not have disabilities was mainstreaming, defined as the educational arrangement of placing students [with developmental disabilities] in classes with their peers without disabilities to the maximum extent appropriate.
Typically, mainstreaming was implemented by having students with disabilities participate in the nonacademic portions of the general education program, such as art, music, and physical education. Most of those students were, however, still enrolled in self contained special education classes; they 'visited' general education classes for a relatively small portion of time. For many educators and parents, mainstreaming provided far too little and came much too late for the students.
Another definition adds some other dimensions – who is "mainstreamed" with what expectations and which supports.
Mainstreaming was a term popularized after the passage of P. L. 94-142 which has been generally used to describe the process of placing a student with mild to moderate disabilities into one or more general education academic classes. Students who are mainstreamed are usually expected to meet the same standards as students without disabilities with minor modifications in curriculum or methodology. Prerequisite skills are generally felt to be necessary since the same standards for success are being applied for all students. This delivery model identifies the child as a "special" rather than a "general" education student. This practice has not typically been associated with students who are identified as having severe disabilities.