Basically, the objectives of ABA are to reduce self-injurious behaviors, increase compliance with adult demands, and thereby improve social and academic skills, and speech/verbal behavior. The child needs to be directly taught to pay attention, imitate, and to comply with simple instructions. They use a lot of operant conditioning principles in treatment.
DIR is what I find most interesting. I believe it encompasses all areas of child development. Objectives of DIR are affect (emotion), social skills, interpersonal communication, self regulation and interest in the world, and capacity for emotionally rich experiences and meanings. Therapists following the floortime model usually use affect to lure a child into an interaction. Also, they set up social and emotional dilemmas so the child can respond to them in a more typical way..