Does special education work?

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The Individuals with Disabilities Education Act turned 50 last year. Many advocates and politicians heralded the anniversary. At the same time, some observers have been wondering how well the law has succeeded in helping students.

A study released Monday sheds new light on this question, offering among the most comprehensive and rigorous answers to date. The findings were strikingly positive. Across three states, access to special education services changed students’ academic trajectories for the better. 

The gains were “immediate, quite large, and sustained,” says Marcus Winters, lead author of the paper and a professor at Boston University.

The results indicate that special education is working to a meaningful extent for many students who are gaining access to additional services. What the study doesn’t answer, however, is whether special education can work even better, considering the significant costs involved.

“The question is how much better should we be shooting for?” says Douglas Fuchs, a Vanderbilt University professor who studies special education.

Under the law, IDEA, once a student is identified as having a disability, they are entitled to an individualized learning plan and support based on that plan. About 15% of public school students are in special education, a figure that has been ticking up in recent years.

To conduct the analysis, a team of six researchers examined a large tranche of student test score data in Connecticut, Indiana, and Massachusetts. They followed students who were identified as having a disability some time between fourth and eighth grade. (This means the study is not able to examine the effect of special education on students identified in earlier grades.)

The pattern in each of the states was remarkably consistent. Before being identified, these students’ performance relative to their peers was trending down. This may have reflected challenges from an undiagnosed disability. But after those same students started receiving special education, they began making substantial learning gains on state math and reading tests.

In other words, they went from losing ground to gaining it back.

With a special education identification, a student at the 30th percentile of performance would be expected to move up between 7-15 percentile points over three years. The estimated size of the improvement depends on whether researchers assume the students would have continued to spiral downward academically without the services or whether they would have stabilized. Either way, these are large effects relative to what education researchers typically find.

Using detailed data from Massachusetts, the study shows that access to testing accommodations, like extra time, is unlikely to explain the learning gains from special education. 

The positive results are fairly consistent across different types of disability categories and student demographic groups. Students from low-income families are more likely to be identified as having a disability, suggesting that special education serves as something of an equalizer.

Other studies have also found benefits from special education, though this new paper is both more comprehensive in covering multiple states and finds larger effects than some prior work. The bottom line, says Winters, is that “students on average are benefiting from when they’re getting these services.”

In one thorough albeit dated analysis, schools spent nearly twice as much on special education students compared to general education peers. Research finds spending matters in education, so it’s perhaps not surprising that students benefit from being identified. 

The new study can’t explain what’s working in special education: whether it’s specific services, extra resources, some combination or something else. Winters says he does not take his findings to suggest everything is working perfectly in special education.

Ashley Jochim, principal at the think tank Center on Reinventing Public Education, says the key question is how the gains from special education compare to the costs. Maybe alternative strategies could produce even larger results.

“While this study meaningfully adds to the evidence base about how special education impacts student learning, I'm not sure it helps us understand whether the current system is working as well as it could, especially in light of the investments we make in it,” she said by email.

Reach me at [email protected].