Six years ago, Georgetown University's Office of International Programs, together with partner institutions, designed a large-scale, multi-year study of U.S. student learning abroad. The data support three broad conclusions with significant implications for study abroad policies and practices. This analysis concentrates for the most part on one conclusion, that is, the study revealed significant relationships between independent variables representing learner characteristics and program features and the intercultural and target language learning of students abroad. The relationships between student learning and certain independent variables support the argument that students learn most effectively abroad given proactive learning interventions. This study, in highlighting a number of learner characteristics and program components that are significantly associated with student learning abroad, has yielded two different types of findings: first, those that call attention to needs for improving student learning; and second, those that suggest interventions that address those needs. The study has identified two intercultural learning needs and suggested six interventions that might be implemented at home campuses prior to departure to increase intercultural learning abroad. It has also identified five intercultural needs that might be addressed abroad through the intervention of a well-trained cultural mentor who meets with students frequently and who designs and delivers those interventions within Sanford's challenge/support hypothesis. (Contains 4 figure, 33 tables, and 37 notes.)