Which term describes the practice of integrating children with special needs only when they can keep up with their peers?

The practice of integrating children with special needs only when they can keep up with their peers is best described by the term "mainstreaming." Mainstreaming refers specifically to placing children with special needs into general education classrooms when they are able to perform at a level comparable to their typically developing peers. This approach focuses on the ability of the child to meet the academic and social demands of the regular classroom setting.

In contrast, inclusion encompasses a broader philosophy of educating children with special needs alongside their peers regardless of their ability to keep pace, promoting the idea that all children should participate fully in the classroom environment. Segregation involves separating students with special needs from their peers, often in entirely different educational settings, while integration typically refers to bringing children with special needs into a general education environment, but doesn't specifically require that the children be able to keep up academically. Thus, mainstreaming aligns closely with the concept presented in the question.