KAREN SMITH MITCHELL. Expanding the conversation among secondary educators toward a shared understanding of student engagement (Under the direction of DR. REBECCA SHORE) To describe how high school administrators and teachers perceive student engagement and how socioeconomic status contextualizes student engagement, the researcher conducted a phenomenological study to generate knowledge of the lived experiences of the participants through semi-structured interviews. As an active participant in the data collection, the researcher explored the experiences of administrators and teachers to generate a robust description of the construct to promote a shared understanding of student engagement within two diverse, secondary, learning communities to support increased student learning outcomes. Research presented in the literature and the findings of this dissertation affirm the role of students as active participants in the educational processes, the Classroom Engagement Framework (Cooper, 2011) as an organizational structure to guide conversations within secondary schools around "Lively Instruction", "Connective Teaching" and "Academic Rigor", and the positive relationship between socioeconomic status and increased student learning. Disparities within the findings suggest incongruence with respect to whose responsibility it is to engage the students, the role of feedback, the development of trust, as well as the importance of the instructional practices to support engagement. The findings of this dissertation suggest the significance of professional development within secondary schools to support increased understanding of the phenomenon of student engagement. Suggestions for future research are presented including; incorporating students’ voices as well as studies conducted in and with teachers of elementary and middle schools to explore the findings. Additional research would contribute to the shared understanding of the operational definition of student engagement and to increased student learning outcomes.