This book focuses on how interactive, multimodal technology such as virtual agents can be used in training and treatment (social skills training, cognitive behavioral therapy). People with socio-affective deficits have difficulties controlling their social behavior and also suffer from interpreting others’ social behavior. Behavioral training, such as social skills training, is used in clinical settings. Patients are trained by a coach to experience social interaction and reduce social stress. In addition to behavioral training, cognitive behavioral therapy is also useful for understanding better and training social-affective interaction.