Policy makers cannot consider all evidence relevant to policy. They use two shortcuts—emotions and beliefs to understand problems and “rational” ways of establishing the best evidence on solutions—to act quickly in complex, multilevel policy-making environments. Many studies only address one part of this problem. Improving the supply of evidence helps reduce scientific and policy maker uncertainty. However, policy makers also combine their beliefs with limited evidence to reduce ambiguity by choosing one of several possible ways to understand and solve a problem. We use this insight to consider solutions designed to “close the evidence–policy gap.”