Mainstreaming does not equal access for students with disabilities, who often still lag behind peers


Mainstreaming does not equal access for students with disabilities, who often still lag behind peers

Evidence in favor of inclusion also fails to account for impact on peers and teachers

July 19, 2018—The Individuals with Disabilities Education Act mandates that students with disabilities (SWDs) receive a free appropriate public education in the least-restrictive environment possible—which usually means including SWDs in general-education classrooms. But has the practice of inclusion gone further than the evidence supports? In a new article for Education Next, Allison Gilmour of Temple University explores what the research tells us about inclusion’s effects not only on SWDs but also on their general-education teachers and peers without disabilities, finding limited evidence that inclusion alone leads to better academic outcomes for SWDs and even less evidence that general-education teachers are prepared to support SWDs in the classroom.

Based on the assumption that exposing SWDs to the regular curriculum will increase their academic progress, the inclusion of SWDs in regular classrooms has become increasingly common in the last 20 years, with more than 60 percent of all SWDs spending 80 percent or more of their school day in regular classrooms in 2016. However, recent research highlights just how far SWDs continue to lag behind their peers. For example, a synthesis of 23 studies finds that the average reading achievement gap between SWDs and their classmates without disabilities is 1.17 standard deviations, or about three years of academic growth.

Other key takeaways include:

Selection bias in existing research. The push to move more SWDs into general-education classrooms has been fueled by a series of studies reporting that more time in such a setting is associated with higher reading and math scores and improved attainment for SWDs. However, these findings likely reflect selection bias: students with higher academic abilities or fewer behavioral challenges are more likely to be placed in inclusive settings.

Potential negative impact on peers. A 2009 study found that having a classmate with an emotional/behavioral disorder (EBD), a common form of disability, was associated with a 0.09 stan­dard-deviation decrease in students’ math scores and a 0.13 standard-deviation decrease in students’ reading scores. A 2016 study reported that students without disabilities who had a classmate with an EBD were 1.42 times more likely to be chronically absent than those who did not have such a classmate.

Gap in teacher preparation. Both surveys and qualitative studies find that general-education teachers often do not have the training, or feel they have the proper skills, to meet the academic and behavioral needs of SWDs while also teaching their non-disabled peers. Using data from North Carolina, Gilmour found that the probability of turnover among general-education teachers increased as the percentage of SWDs in teachers’ classes went up, with the increase especially pronounced when teach­ers had students with EBDs in their classrooms.

Gilmour advises that decisions about inclusion should be made on a individualized basis and take an ecological perspective, weighing the effects of classroom interactions between SWDs, their peers, and general-education teachers. “Policymakers and school personnel should keep in mind the limited evidence base suggesting that placing an SWD in a general-education classroom will result in the student making progress in the general-education curriculum,” warns Gilmour, noting that location should not be used as an indicator of access. “Special education is an amalgam of services, not a place.”

To receive an embargoed copy of “Has Inclusion Gone Too Far? Weighing its effects on students with disabilities, their peers, and teachers” or to speak with the author, please contact Jackie Kerstetter at The article will be available Tuesday, July 24 on and will appear in the Fall 2018 issue of Education Next, available in print on August 30, 2018.

About the Author: Allison F. Gilmour is assistant professor of special education at Temple University.

About Education Next: Education Next is a scholarly journal committed to careful examination of evidence relating to school reform, published by the Education Next Institute and the Harvard Program on Education Policy and Governance at the Harvard Kennedy School. For more information, please visit

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