Researchers often rely on undergraduate students to participate in psychological studies and so ethical guidelines state that there must be educational value to their participation. In previous studies that have asked undergraduates whether they felt they learned something new from participating in research, students have generally said yes. However, we know relatively little about what specifically they are learning. The current study aimed to extend previous research by asking undergraduate participants (N = 479), who had all taken part in at least one psychology study, to indicate whether and what they learned about the research process, themselves, or other people as a result of their participation. Participants were also asked to recommend ways to make participating in studies more educational. Our findings suggest that the majority of participants are learning from their participation, most often about the design or process of research but also sometimes about their own psychology or that of other people. Based on students' feedback, we provide specific recommendations for further improving the educational potential of studies.