Impact assessment research has developed theory-based approaches to trace the societal impact of scientific research. Impact assessment typically starts from the perspective of a research investment, organization, or project. Research users, non-academic actors involved in knowledge production, translation, and application, are well represented in many of these approaches. Researcher users are usually positioned as contributors to research, recipients of research outputs, or beneficiaries of research-driven outcomes. This paper argues that impact assessment would benefit from a more comprehensive understanding and analysis of research valorization processes from the user perspective. The first half of the paper reviews key impact assessment literature to identify how research users are positioned and portrayed in relation to valorization processes. In the second half of the paper, we use the results of this review to propose a set of principles to guide a systematic approach to constructing user perspectives on research impact. We suggest four concepts for operationalization of this approach. The paper concludes that the addition of a more comprehensive research user perspective on research valorization would complement and enhance existing impact assessment approaches.