SUNY defines service learning as "A credit-bearing educational strategy that integrates meaningful community service with instruction and reflection to enrich the learning experience and strengthen communities" (SUNY Applied Learning, emphasis added). Reflection is therefore an essential part of service-learning and applied learning more generally. Reflection helps students to learn academic content, learn about themselves and others, and consider their role as citizens and allows instructors to assess student learning. The following resources delve deeper into the purpose of reflection and methods of implementation.
The Craft of Community-Engaged Teaching and Learning by 
Service Learning Reflection Journal by 