Relationship Development Intervention® (RDI®) is a treatment program developed by Dr. Steven Gutstein and his wife, Dr. Rachelle Sheely in effort to achieve better quality of life for people with Autism Spectrum Disorders.  Dr. Gutstein’s measurement of quality of life includes independent living, jobs at the individual’s skill or cognitive level, and friendships. Preliminary research and anecdotal report indicate that children are improving their ability to participate in genuine emotion sharing in their relationships with family and friends.
RDI® is a family centered approach that is the first intervention that targets the core deficits of Autism. The development of RDI® was based on a comprehensive review of research in typical development, autism, autism treatments, communications theory, systems theory, cultural and anthropology research, psychotherapy, brain development and function, developmental psychology and more. Treatment of autism through RDI® follows the path of typical development and is achieved through structured ‘lab times’ and the practice of the RDI™ principles and techniques throughout the daily activities of life.  “Each program is individually constructed for the child's specific needs in order to decrease the child's obstacles and utilize their strengths to develop meaningful relationships, cognitive flexibility and relative information processing.” Parents function as the primary interventionists with their children under the direction of a RDI® Program Certified Consultant.
Participation in RDI® begins with the completion of a parent interview, provision of a 30-40 minute base-line video of your child in typical daily activities, administration of the Autism Diagnostic Observation Scale (ADOS), six to eight hours of parent training and then completion of multi-step Relationship Development Assessment™ (RDA™) with your consultant. The information gathered in these steps is combined to develop a customized treatment plan to assist you in helping your child develop the motivation and subsequent skills to share in meaningful relationships with others. “It is recommended that each family have formal RDI® sessions progressing towards five to six hours a week. However, the greatest success is seen in families who have an "RDI® lifestyle" in addition to the more formal sessions. Families are taught to use their objectives and frameworks within everyday activities to speed up progress and ensure generalization.” (quoted from www.rdiconnect.com) Treatment plans are developed for a period of 6 months and include regular videotaping of work with your child at home. The treatment plan will represent a custom combination of clinic sessions, video review and written feedback and parent conferences. Assessments are repeated at six month intervals and treatment plans are revised.
Quotes are from  http://www.rdiconnect.com/RDI/FAQ_Fam.asp