Students in a self-contained class are not exposed to children other than the ones in their class. That may be a problem, depending on a particular child's individual needs and preferences. Students in the self-contained class do not get the benefit of experiencing different environments throughout the day. If a student likes having different teachers and a mixture of friends, and does well in inclusion classes, a self-contained class may not be to his benefit.
One disadvantage for teachers of self-contained classes is that they do not see a variety of children throughout the course of the day. If the teacher is having trouble with a student in a self-contained class, the teacher does not have the option of getting a break from that student. On the flip side, the child also does not get a break from his teacher.
Some educators and parents argue that students do better academically and socially in an inclusion class than a self-contained class. On the other hand, a self-contained class can ultimately have a more cohesive, family-like feel and more consistency because the child stays put. Some children find this environment beneficial.
A self-contained class can be disadvantageous if the quality of the program is poor. According to the Principals Parternship website, it's not the self-contained environment itself that leads to success but the teacher and program standards oin the environment that make the difference.