The "Lovaas Model of Applied Behavior Analysis" is a type of behavioral therapy that initially focuses on discrete trials: brief periods of one-on-one instruction, during which a teacher cues a behavior, prompts the appropriate response, and provides reinforcement to the child. Children in the program receive an average of 35 to 40 hours of intervention per week, which consists of in-home one-to-one instruction, facilitated peer play, inclusion and support in regular education classrooms, and generalization activities for transfer of skills to natural environments. In addition, parents are trained in instructional techniques. The intervention generally lasts about three years. The What Works Clearinghouse (WWC) reviewed 58 studies on the "Lovaas Model" for children with disabilities. One study meets WWC evidence standards; one study meets WWC evidence standards with reservations; the remaining 56 studies do not meet either WWC evidence standards or eligibility screens. Based on the two studies, the WWC found potentially positive effects on cognitive development for children with disabilities and no discernible effects on communication/language competencies, social-emotional development/behavior, and functional abilities. The conclusions presented in this report may change as new research emerges. Appendices include: (1) Study characteristics; (2) Outcome measures; (3) Summary of study findings included in the ratings; (4) "Lovaas Model" ratings; and (5) Extent of evidence by domain. (Contains 12 footnotes.)