Previous research shows that personal epistemologies—individual conceptions of knowledge and knowing—can be domain-specific and domain-general. Individuals can hold general beliefs about science, but they also make distinctions in relation to particular domains of knowledge. This chapter is based on the analysis of the perspectives of a group of participants engaged in a public consultation featuring four rounds of group discussions on climate change, vaccines, complementary and alternative medicine, and GMOs in science communication. Using vignettes to illustrate individual positioning, we explore the knowledge they used to justify their opinions and the roles they attributed to science and expert knowledge as they discussed each topic. Our findings reveal that professional and academic backgrounds, personal experiences, and relationships shape the way participants think, interpret, and evaluate science in different ways. Moreover, citizens’ personal epistemologies towards different science-related issues tend to reflect general beliefs about knowledge while also being influenced by domain specificity. This work contributes to highlighting the importance of personal epistemologies in the study of how trust in scientific expertise is contextually interpreted in everyday life. The research is based on fieldwork conducted in Portugal under the EU-funded (H2020 SwafS) research project CONCISE.