Although most focus group theorists consider interaction to be a defining feature of focus groups, the influence that occurs through this interaction has been under-theorized. We argue that two important forms of influence may occur: influence on people's beliefs about the substantive issues under discussion and influence on self-efficacy beliefs. As a result of such influence, focus groups provide a learning context that may facilitate empowerment of participants through the development of communicative self-efficacy as they struggle over constructing and sharing understandings of controversial issues. As part of a larger research project on dialogues about science, we present a case study that puts qualitatively analyzed transcripts of interaction and quantitative self-report measures into empirical conversation. The case study demonstrated that focus group participants were influenced in two important ways: participation and interaction led to increased participant confidence and motivation towards participating in public dialogues and to the construction, modification, and contestation of attitudes toward science, scientists, and biotechnology. Findings suggest that scholars should rethink their rationales for and use of the focus group as just a method of data collection and reconsider and explore alternative ways of presenting focus group results.