Applied Behavior Analysis has proven to be the most effective means of teaching children diagnosed with autistic-spectrum disorders. ABA is not, however, "one size fits all." Different teaching techniques within ABA must be chosen, based upon student need. In Graduated Applied Behavior Analysis, Dr. Bobby Newman and colleagues describe an approach that alters teaching methodologies based on the functioning level of the student. While there are many schools of thought within ABA, they are all part of the same basic science. Aspects of that science are outlined. Portions of an introductory manual and a study describing the effectiveness of an ABA preschool are included.