The process of determining whether a source of information is relevant is multidimensional, dynamic, and subjective. This essay puts information science scholarship on relevance, including the process and nature of making relevance judgments, in conversation with models of teaching and learning information literacy. Teaching librarians are encouraged to recognize students' relevance judgments as sites of reflection and instruction. This essay suggests a variety of ways librarians might do this, from re-thinking source evaluation methods to emphasizing the opportunities available at the source selection stage. The process of determining relevance is a practical site of reflective possibility and deserves greater attention in information literacy teaching and learning. Discussing relevance judgments can help students better understand and evaluate sources, reflect on their own and others' perspectives and motivations, and create opportunities to discuss the impact of information systems.