This project addresses classical epistemological questions in a novel manner, prompted by one of the most significant developments within welfare services in the past three decades, namely evidence-based practice (EBP). Key methodological tools for operationalizing EBP have included systematic reviews, guidelines, and manuals aimed at enhancing quality, equity, and mitigating arbitrariness and unnecessary variation. Critics, however, highlight extensive issues: evidence is often generated under circumstances divergent from application contexts, disseminated without regard for professional judgment, resulting in relevance deficiencies and hindrances for the services. This raises important and longstanding epistemological questions concerning validity, objectivity, causality and professional judgment. These have frequently been embroiled in contentious debates, referencing strongly contrasting philosophical schools, such as positivism and hermeneutics. In this project, alternative theoretical resources and a plethora of empirical findings from science and technology studies are utilized to transcend such polarized epistemological debates. The project delves into the underlying epistemological assumptions of EBP and explores how these can be broadened and operationalized in alternative ways. Thus, more methodological avenues are made available for welfare actors to achieve the goals that have characterized EBP from its inception.