by Susan Chira

About the author: Susan Chira is a reporter for the New York Times.

Merari Vazquez’s fellow second and third graders are learning about perimeters. Measuring is hard for Merari, who is mentally retarded and does not speak. But she is part of the group, and her classmates need to find a way she can work with them. They coax her to lie down on a big pad, using her to do their measuring.

A Controversial Experiment

Merari is part of a bold but hotly debated educational experiment: teaching even severely handicapped children in regular public school classrooms instead of separate ones. The idea goes far beyond “mainstreaming,” which usually involves milder disabilities; at schools like Merari’s, no heads turn at children using wheelchairs, feeding tubes or oxygen tanks.

Schools like those in...