Many students receiving special education services are supported by one-to-ones, but new research suggests these assistants may not be pulling their weight.

A study looking at how one-to-ones spent their time in nearly four-dozen autism support classrooms finds that paraprofessionals are engaged in instruction or support just 57 percent of the time.

By contrast, teachers were engaged in such activities 98 percent of the time while classroom assistants were involved 91 percent of the time.

“The low rate of one-to-one assistants’ engagement suggests an inefficient use of an important resource,” wrote researchers from the University of Pennsylvania, University of Washington and the University of California, Riverside in their findings published online this month in the journal Teacher Education and Special Education.

The findings are significant, researchers said, because one-to-ones are the fastest growing group of special education staffers.

For the study, researchers looked at 46 autism support classrooms serving students in kindergarten through second grade in a large, urban school district. All of the classes included a lead teacher and a classroom assistant, but the number of one-to-ones varied from none to 16. Engagement among the professionals in each classroom was assessed through monthly observations over the course of a school year.

Overall, one-to-ones were engaged slightly over half of the time. When they weren’t busy, however, about a third of one-to-ones “spent their time sitting without students or material involvement,” the study found.

Significantly, the findings suggest that one-to-ones perform better if they work alongside a highly-engaged classroom assistant.

Researchers said the relatively low level of involvement among one-to-ones could be a sign that they are poorly trained on how to work with students or that classroom teachers are ill-prepared to supervise such staff. What’s more, the researchers said that one-to-one engagement may be the result of a fragmented service system in which it’s often unclear who is responsible for training, supervising and evaluating these employees.

“In an era of increasing utilization of one-to-one assistants, there is an underlying assumption that expanding their use is necessary and desirable. The lack of engagement observed in our study raises concerns about the effectiveness of current models and may be symptomatic of broader challenges related to the delivery of special education services,” the researchers wrote in their findings.