2. Scientific Evidence in Policy Processes: Concepts and Histories

Although there are countless examples of science informing policy over the nineteenth and twentieth century, theory relating to how this process happens has evolved significantly in recent years. Today there are three dominant schools of thought which consider how evidence can be used to inform policy outcomes; political science, decision-making theory, and policy studies. Political science emphasises the design of evidence, through classical models of social enquiry, as fundamental to ensuring political impact (Green 2005). Decision-science or decision-making theory emphasises the processes of deliberation and contestation through which decisions are reached thereby highlighting potential entry points at which evidence can be presented (Goldie et al. 2006). Meanwhile policy studies emphasises the process of policy formulation, with models ranging from decade-long cycles, to messy non-linear processes of coalitions weighing-up evidence inputs, beliefs, and political influences to design and advocate for interventions (Sabatier 1988; Cairney 2013). The most expansive literature on evidence to policy-uptake stems from the field of policy studies referred to as Evidence-Based or Evidence-Informed Policy (EBP / EIP), which has borrowed heavily from the evidence-based practice movement which started in medical research.