Little is known about knowledge transfer with the public. We explored how citizens, physicians, and communication specialists understand knowledge transfer in public spaces such as libraries. The initial study aimed at evaluating the scaling up of a program on disseminating research findings on potentially inappropriate medication. Twenty-two citizen workshops were offered by 16 physicians and facilitated by 6 communication specialists to 322 citizens in libraries during spring 2019. We did secondary analysis using the recorded workshop discussions to explore the type of knowledge participants used. Participants described four kinds of knowledge: biomedical, sociocultural beliefs, value-based reasoning, and institutional knowledge. Biomedical knowledge included scientific evidence, research methods, clinical guidelines, and access to research outcomes. Participants discussed beliefs in scientific progress, innovative clinical practices, and doctors’ behaviours. Participants discussed values related to reliability, transparency, respect for patient autonomy and participation in decision-making. All categories of participants used these four kinds of knowledge. However, their descriptions varied particularly for biomedical knowledge which was described by physician-speakers and communication specialists-facilitators as scientific evidence, epidemiological and clinical practice guidelines, and pathophysiological theories. Communication specialists-facilitators also described scientific journalistic sources and scientific journalistic reports as proxies of scientific evidence. Citizens described biomedical knowledge in terms of knowledge to make informed decisions. These findings offer insights for future scientific knowledge exchange interventions with the public.