The purpose of this book was to provide an overview of evidence-based training practices, specific examples within various contexts and skills, and the importance of effective and efficient training as it relates to ABA-based interventions for individuals on the autism spectrum. The contributions to this book from each of the invited authors are invaluable. They highlight the many considerable challenges and advancements related to training thoroughgoing behavior analysts to operate as quality autism interventionists. However, just as applied behavior analysis is a science and, as such, is progressive, our practice that is informed by that science should be progressive as well. Thus, despite the many efforts contributing to advancements in training thoroughgoing behavior analysts, there are many areas ripe for improvement. The purpose of this chapter is to highlight some of those possible areas.