Despite recent studies of researchers’ roles in sustainability science, understanding the factors that influence them is a complex challenge. To address this lack of knowledge, we conducted a self-reflexive analysis involving 11 researchers from Rennes, France, who self-reflected on 12 projects conducted in north-western France over the past 15 years. This study investigates the roles of researchers in sustainability science projects by clustering these projects based on their characteristics and by evaluating the roles researchers assumed within each cluster. Four clusters were identified, ranging from academic research with minimal stakeholder involvement to highly interdisciplinary and transdisciplinary projects with significant stakeholder engagement. Researchers adopted multiple and dynamic roles, influenced by project characteristics but not deterministically. The role of transdisciplinary dialogue facilitator was frequently filled by intermediaries rather than researchers, highlighting a skills gap or a misalignment with traditional metrics of research performance. Self-reflection was significant in managing complex interdisciplinary and transdisciplinary projects, especially in clusters dealing with real-world problems and stakeholder interactions. The methodology, based on qualitative interviews and project clustering, proved effective and suggests that future research should include broader data collection and explore individual factors about mindset and motivation which influence researchers’ roles. These findings emphasise the need for better support and recognition of diverse roles in academic evaluation and suggest the potential benefits of specialised intermediaries in transdisciplinary research.

Despite recent studies of researchers’ roles in sustainability science, understanding the factors that influence them is a complex challenge. To address this lack of knowledge, we conducted a self-reflexive analysis involving 11 researchers from Rennes, France, who self-reflected on 12 projects conducted in north-western France over the past 15 years. This study investigates the roles of researchers in sustainability science projects by clustering these projects based on their characteristics and by evaluating the roles researchers assumed within each cluster. Four clusters were identified, ranging from academic research with minimal stakeholder involvement to highly interdisciplinary and transdisciplinary projects with significant stakeholder engagement. Researchers adopted multiple and dynamic roles, influenced by project characteristics but not deterministically. The role of transdisciplinary dialogue facilitator was frequently filled by intermediaries rather than researchers, highlighting a skills gap or a misalignment with traditional metrics of research performance. Self-reflection was significant in managing complex interdisciplinary and transdisciplinary projects, especially in clusters dealing with real-world problems and stakeholder interactions. The methodology, based on qualitative interviews and project clustering, proved effective and suggests that future research should include broader data collection and explore individual factors about mindset and motivation which influence researchers’ roles. These findings emphasise the need for better support and recognition of diverse roles in academic evaluation and suggest the potential benefits of specialised intermediaries in transdisciplinary research.