Applied Behavior Analysis (ABA) is very commonly recommended for children with autism, severe mental retardation and other severe disabilities. In short, ABA identifies a specific behavior we want the child to learn, breaks it down into small steps and reinforces each step. For example, if we want the child to learn to put on her own clothes, we might start with giving her a stick of gum when she puts on her own shirt. After she has learned that, we might require that she put on her own pants and shirt before getting a stick of gum, etc.
As each individual behavior must be directly taught, e.g., put on your socks, put on your shirt, put on your pants are all taught individually, ABA can be very time consuming and take a lot of effort from caregivers. SO… the lesson is to choose the behavior to be learned carefully. Is it really important that the child learn to tie his own shoes or can you just have him wear slip-on shoes or shoes with Velcro and spend the time teaching him how to feed himself?
As mentioned, ABA is very time intensive and expensive. You are paying someone hours each and every day to work one on one with a child.