Book excerpt: The Teaching Pyramid Infant-Toddler Observation Scale (TPITOS(TM)) is an assessment instrument designed to measure the fidelity of implementation of practices associated with the Pyramid Model in center-based infant and toddler care settings. The TPITOS provides a classroom snapshot of the adult behaviors and classroom environment variables associated with supporting and promoting the social-emotional development of infants and toddlers. The tool is made up of items, or categories, of teacher behavior. The three types of items are a) Observational Items, b) Interview Items, and c) Red Flag Items.