Without formal training, one could certainly use behavioral principles to modify behavior. In fact, people do it everyday without really being aware that it is ABA that they are using. To be as effective as possible, however, some form of consultation with a behavior analyst is needed, particularly if we're talking about early and intensive behavioral therapy for a child with special needs. There are many ways to get it wrong, at least insofar as progress could be impeded and unwanted behavior could be strengthened unintentionally. Once you are sufficiently trained and experienced, however, you can certainly use ABA techniques effectively. In fact, we are counting on it. When you receive our services, you will eventually be skilled enough to collect reliable data, evaluate those data, and to recognize both the need and methods required to change behavior by changing the environment.