Realising the societal gains from publicly funded health and medical research requires a model for a reflexive evaluation precedent for the societal impact of research. This research explores UK Research Excellence Framework evaluators' values and opinions and assessing societal impact, prior to the assessment taking place. Specifically, we discuss the characteristics of two different impact assessment extremes--the "quality-focused" evaluation and "societal impact-focused" evaluation. We show the wide range of evaluator views about impact, and that these views could be conceptually reflected in a range of different positions along a conceptual evaluation scale. We describe the characteristics of these extremes in detail, and discuss the different beliefs evaluators had which could influence where they positioned themselves along the scale. These decisions, we argue, when considered together, form a dominant definition of societal impact that influences the direction of its evaluation by the panel.