The development of different treatment methods in the developmental disorders were varied and in the present article the research of 30 years regarding the treatment of Ivar Lovaas from University of California in the year 1993 is being described here. The research was based on the description of all other researches from the previous 30 years from the year 1993. The research stresses on the method of application of treatment rather than on the focus on the theoretical cases. The practical application will mean the application of the theories step by step in a cumulative fashion.