Determining if a mentee understands the content and process of their discipline is not easy, and yet it's critical in a productive mentoring relationship. Developing strategies to assess understanding, especially of core research concepts, is an important part of becoming an effective mentor. As part of an ongoing series of trainings for faculty who mentor graduate students, this session dives into how to assess and promote understanding. During this workshop, we will explore different environments and approaches that mentors can utilize to help mentees understand specific topics and build self-efficacy.