A frequently asked question from parents, therapists and teachers is how to treat autism spectrum disorder (ASD) successfully. These questions, often asked by parents, therapists and teachers, are answered in this practice manual. The Applied Behaviour Analysis (ABA) and Autism-specific Behaviour Therapy (ABT) are regarded as the most successful methods for children with autism. Concrete steps are shown toward the elimination of behavioural problems and for the development of cognitive, social and communicative abilities. The third edition of this proven specialist book provides updated sequences of the STeP curriculum, task analyses and advice on new learning opportunities through mobile apps.