Collection and analysis of longitudinal observational data of child behavior in natural, ecologically valid, non-laboratory settings holds significant benefits for advancing the understanding of autism and other developmental disorders. We developed the Speechome Recorder�a portable version of the embedded recording technology originally developed for the Human Speechome Project�to facilitate cost-effective deployment in special-needs clinics and homes. Recording child behavior daily in these settings will enable us to study developmental trajectories of autistic children from infancy through early childhood, as well as atypical dynamics of social interaction as they evolve on a day-to-day basis. Its portability makes possible potentially large-scale comparative studies of developmental milestones in both neurotypical and autistic children. Data-analysis tools developed in this research aim to reveal new insights toward early detection, provide more accurate assessments of context-specific behaviors for individualized treatment, and shed light on autism.