This document provides tools and guidance for observing learners' characteristics across different developmental domains and age levels. It includes observation checklists for physical, social, emotional, and cognitive domains. The observer is asked to record their findings in a development matrix to allow comparisons across levels. Their analysis should identify salient characteristics of observed learners and implications for teaching methods. The observer is also prompted to reflect on how their own experiences compare to the learners, recall influential teachers, and share other insights. The portfolio section encourages applying Erik Erikson's psychosocial development theory to guiding one's teaching.