In this paper, the author describes an ethnographic study of a graduate-level practicum at a large Midwestern university in order to examine one of the ways urban planners develop expertise. The graduate students in the practicum were guided in the production of a site plan for a developing area by a planner with 34 years of planning experience. In the study, the author used epistemic network analysis to examine the presentation feedback sessions in order to explore emergent relationships between the teacher's planning expertise and the students' expertise. These results have the potential to influence the future design of professional practicum environments as well as the broader landscape of education. (Contains 3 tables and 12 figures.)