The Ziggurat Model is unique. It is simple to use while being comprehensive and thorough. While it is easy to find volumes of information describing specific interventions, it is difficult to find information on how to develop an intervention plan. This textbook presents a process and framework for designing comprehensive interventions for individuals of all ages with autism spectrum disorders. Recent trends in special education law emphasize the use of scientifically based research approaches along with a focus on response to intervention (RTI). Additionally, there is a strong push for incorporating positive behavioral interventions and supports (PBIS) based on a functional behavioral assessment. The Ziggurat Model is consistent with these practices. While The Ziggurat Model is designed to address the needs of all individuals with autism spectrum disorders, the case studies in this textbook focus on the higher functioning population.