Do Policymakers Cite or Mention? Investigating Formal vs Informal Engagement in Policy Documents and the Implications for Responsible Research Assessment

As policy impact grows in importance within research assessment frameworks, how policymakers actually engage with research has consequences for how that impact is measured, valued, and rewarded. This study examines modes of research engagement in government documents, distinguishing formal citations from informal mentions of researchers, organisations, and policy actors. Using the Overton database, we drew a random sample of 50 UK government documents from 2025 and manually coded each for formal citations (to peer-reviewed papers or other policy outputs) and informal mentions (of researchers, organisations, or funders lacking a bibliographic reference), alongside Overton's AI-generated document type classifications. We identified over 2,000 references and mentions, with informal mentions substantially outpacing formal citations, though the balance varied by document. Government-commissioned research and consultations were mentioned more often than peer-reviewed outputs. These findings indicate that citation-based indicators alone may miss some of the influence of research within policy, which may raise questions for researchers and disciplines whose engagement may take a non-citable format. We explore examples in more detail and discuss implications for responsible research assessment and the growing role information professionals could play in surfacing informal engagement. We also present initial data from a larger-scale follow-up study extending this coding framework across multiple countries, organisational types, and policy areas, offering an early view of whether these engagement patterns hold beyond a single national policy context - with direct implications for how research assessment frameworks might account for policy influence more equitably and comprehensively.