Case studies were conducted of four female cooperative education (co-op) students who participated in two 4-month co-op placements in a veterinary clinic as part of a high school biology credit. Two graduate students gathered data onsite during two phases: an initial 2-month period that oriented the methods of the inquiry at the clinic to match what was witnessed and observation and data collection during the last 2 months of the first placement and the second placement. Early in their placements co-op students learned simple tasks they were expected to complete without supervision. Assuming such responsibilities made them immediately feel like contributing team members and motivated them to complete the tasks proficiently so they could later be available to observe and participate in animal treatment. Students learned the relationship of the routines to the clinic's priorities and the science behind the activities in which clinic personnel engage. Two main types of opportunities for learning were tasks they performed and activities they observed and participated in peripherally. Clinic staff enhanced learning through questioning in the context of direct observation, think-alouds, cueing, and direct instruction. Two features of these approaches were that they reflected priorities of the clinic and they took place in the context of experience. The gradation in responsibility had dimensions in the workplace: complexity of tasks and responsibilities, risk if errors are made, and subject matter undergirding placement activities. (Contains 15 references.) (YLB)