L.D.
ABA is a method of teaching children with ASD in a manner that is meaningful to them. I'm a little bit too tired right now to go into how ABA is structured and how it works but, I have to say that this program has been a lifesaver for our son -- actually, our entire family.
My son is also high functioning. He started ABA when he was 4 and was talking but a lot of it was labeling which is not very functional. He could ask for "more" but couldn't tell us other things like if he felt sick, was hungry, tired or cold -- stuff that other parents of 4-year olds take for granted. He had a lot of attentional issues and behavior issues also. No stranger danger, had a tendency of disrobing when he was frustrated or tired (not very good when we are at some place like the park or pump-it-up), and just a lot of other things that gave him the autism diagnosis. But he also was very cute and had a lot of strong skills as well.
We have been doing ABA now for 3+ years and I credit it for him being able to attend a general ed 2nd grade class 99% (with special ed support), being able to start conversations with other people and maybe have a 3 or 4 part exchage, improving his handwriting and his cognitive skills (so that he can be in general ed), helping him learn how to ride his bike (although he still has training wheels, but that pedalling motion is really tough for a kid with motor planning issues), and a host of other skills that he has picked up along the way.
We have been lucky enough to have a consultant and tutors who really like my son and see him for who he is and not just as a diagnosis. As a result, our ABA program is tailored to fit his skills and deficits. Right now some of the things we are working on handwriting (always a work in progress), reading out loud and asking/answering questions, how to tell whether something he wants to talk about is interesting to another person, answering the phone and having a conversation, riding his bike, and staying on task while doing classwork. We have been doing ABA for 3+ years now and have gone through a lot of programs. Everything from verbal and and non-verbal imitation, telling jokes, starting a conversation, giving instructions, learning to draw.
Anyway, there's a lot I can tell you about the program but, if you have any specific questions, please feel free to PM me and I'll be glad to answer them them for you.
Hope this helps.