The purpose of this study was to determine the impact of a year-long, same school classroom social skills instruction program on students' with verified Emotional Behavior Disorders, Autism Spectrum Disorders, and Attention Deficit Hyperactivity Disorders perceptions of program effectiveness. This study indicated that youth can demonstrate pro-social replacement social skills and reflects that students, parents, and teachers differ in their perceptions of how well the social skill instruction is impacting student outcomes in the areas of inattention, hyperactivity/impulsivity, learning problems, and defiance/aggression as measured by the Conners 3 Rating Scales. The results of this study suggest that when children and youth with Emotional Behavior Disorders, Autism Spectrum Disorders, and Attention Deficit Hyperactivity Disorders are provided with intensive social skill instruction they will demonstrate fewer undesirable behaviors. However, when reporting Perceptions for Hyperactivity/Impulsivity Parents, Teachers, and Students were found to be in disagreement about student progress in this important domain where Parents Very Elevated when reporting Perceptions for Defiance/Aggression Parents, Teachers, and Students were found to be in disagreement about student progress in this domain where Parents Elevated level of concerns and Teachers Very Elevated level of concern scores were found to differ significantly from Students Average reported perceptions of their own Defiance/Aggression scores. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]