This seems like one of those situations where it becomes difficult to determine who is being helped more, the special needs students, or the student providing their time to help them. I'm sure it's a very rewarding exercise for the advanced students to help others who need extra attention and support. Also, the interaction is great for all of the students involved and I'm sure the special needs students are grateful to be able to spend time with the advanced students and to see them take an interest in their problems and to have them work together to find ways to better teach and learn the information.