Infants expect agents to act rationally in pursuit of their goals. However, little research has considered whether children expect other agents to learn rationally. In this project, we are investigating 4.5- to 6-year-olds’ reasoning about another agent’s beliefs after the agent observes a sample drawn randomly or selectively from a population. Do children who can correctly track both the true state of the world and the other agent’s initial beliefs expect the agent to learn rationally by updating his prior beliefs only when warranted by the evidence? This work allows us to ask whether the ability to integrate these factors underlies an understanding of how evidence informs others’ beliefs.