Background A persistent challenge in patient and public involvement (PPI) is the representativeness of PPI contributors. Maguire & Britten (2017) identified multiple co-existing and often conflicting understandings of what it means to “represent” others [1]. Patient organisations often face tensions between democratic legitimacy and practical constraints in acting as representatives [2]. Guidance on representativeness emphasises that demographic mirroring is rarely achievable or appropriate [3]. Aim To propose a small-world network hypothesis that offers an alternative, scientifically grounded understanding of representativeness in PPI. Hypothesis The representational value of PPI contributors can be derived primarily from their structural position and relational connectivity within health, social and community networks, not from demographic proportionality. Small-world network research shows that a limited number of well-positioned bridging nodes can efficiently connect diverse clusters and enable broad informational flow across a system [4,5]. Implications for PPI Practice Experienced PPI contributors frequently occupy such bridging roles, drawing on informational flow of lived experiences from a variety of clinical and social care settings as well as from support networks with diverse demographics. Assessing representativeness through relational and structural diversity may therefore be surprisingly more effective than relying on demographic matching alone. Conclusion A small-world network perspective offers a testable and conceptually coherent reframing of representativeness in PPI. It clarifies who can legitimately contribute and why, opening new directions for empirical research and practical guidance. References: [1] Maguire K, Britten N. Soc Sci Med. 2017;183:62–69. [2] Fischer J, Van de Bovenkamp HM. Health Policy, 2019;123(1):109-114. [3] National Health Council. Tackling Representativeness: A Roadmap and Rubric. 2019; 17p. [4] Watt D., Strogatz S. Nature 1998;393:440–442. [5] Samoylenko I, Aleja D, Primo E, et al. Phys Rev X. 2023;13:021032.