Problems with nonverbal social interaction are characteristic of autism spectrum disorder (ASD). Such problems include impaired ability to detect as well as express emotions, termed facial emotion recognition (FER) and emotion expression (EE), respectively. Computer-based, automated training systems to target these mechanisms hold tremendous promise for moving the field of interventions for ASD forward. We propose to develop a highly transportable, low-cost, and user-friendly technotherapy system that targets both FER and EE. This system [Facial Emotion Expression Training: FEET] will be entirely non-invasive and game- like, to make it appealing to the target population - children with ASD. This new system will be technologically sophisticated as it uses 3D sensors, allows for free movement of the user, and automatically adjusts stimuli presentation based on real-time feedback from the user (the child). Additionally, we are integrating best practices in the field ofASD intervention research, in that the system is individualized and delivery of stimuli will be scaffolded, based on the responses (accuracy) of the user. In this two-year study, we will first refine the computational system used by the system to maximize accurate computer emotion detection with children. We will then examine usability, feasibility, and assessment validity of th new system using a two-group study comprised of children with ASD (n=20) and children without ASD (n=20). This is not a treatment evaluation study, but rather a proof of principle study, the goal of which is to optimize the technology that will be used in intervention. The penultimate goal of this line of research is to develop an innovative treatment approach that targets core processes that underlie manifest social deficits in children with ASD. Such an approach has transdiagnostic appeal as poor FER/EE is not specific to ASD; it is commonly found in children with ADHD for example. This research is also necessary to establish viability of the system before proceeding to efficacy evaluation, which will be the next step.