Compassion is a complex skill involving both psychological (invisible) components and behavioral (visible) manifestations. In a new generation of Social-Emotional Learning programs that target compassion like Social, Emotional, and Ethical Learning (SEE LearningTM), these skills are hypothesized to both develop naturally and to be cultivated intentionally through enrichment efforts. The challenge is that few developmentally appropriate, behavioral performance-based measures of compassion exist to test the primary impact of compassion cultivation programs for school-aged students on their compassion, a primary effect hypothesized to mediate secondary-order program impacts (resilience, social-emotional wellbeing, physical health, and positive relationships) in students. Furthermore, the challenge is to create new measures in an ecologically valid manner that assesses both the underlying skills and behavioral outcomes in developing children. The model of compassion we use has implicit in it a series of developing subskills that comprise compassion across development. In the proposed study, we aim to design and test the reliability and validity of a performance-based measure of compassion for school-aged children. We will also examine the measure for sensitivity to intervention via an evaluation of the SEE Learning program. We hope that this measure is used by anyone interested in assessing compassion in children.