Cash and colleagues shift the problem of scientific relevance from the quality of isolated findings to the architecture of relations through which knowledge becomes actionable. Their decisive proposition is that effective knowledge systems must simultaneously negotiate credibility, salience and legitimacy: scientific adequacy, practical relevance and procedural fairness are not supplementary virtues but coupled conditions of use. The methodological operation is therefore institutional rather than merely epistemological. Communication, translation and mediation become forms of boundary work that organise exchanges between expert communities, decision-makers and heterogeneous publics while retaining differences in norms, evidence and authority. The paper’s enduring contribution lies in treating knowledge-action interfaces as designed systems whose performance depends on how boundaries are managed rather than erased. This approach provides a crucial bridge between science and technology studies, sustainability governance and later transdisciplinary research, where the production of knowledge increasingly appears inseparable from the infrastructures, procedures and social relations through which claims acquire public consequence.