This paper explores the application of the card-sorting interview technique in understanding the complex interplay of motivations and barriers faced by adults engaging in learning. Traditional research methods, whether quantitative or qualitative, often fail to capture these nuanced interactions or to provide scalable insights for policy development. Card-sorting, which involves sorting and reflecting on physical or virtual cards, offers a middle ground by facilitating deeper reflection and quantification. An empirical study with 69 disadvantaged adult learners highlights the advantages of this technique. Card-sorting enables active engagement, response revision, and comfortable discussion about sensitive issues. It promotes ownership of the results and reduces interview duration while maintaining data depth and richness. Additionally, it balances structured analysis with personal expression flexibility and allows for the quantification of response patterns. The study demonstrates that card-sorting can effectively uncover the interplay of factors influencing adult learning decisions, offering actionable insights for policymakers involved in adult learning. Preliminary findings have already attracted significant interest from policymakers, emphasising the need for refined insights to develop more effective support systems. Future research should explore the feasibility of online card-sorting to enhance scalability and participant comfort.