Policy and program design is a major theme of contemporary policy research, aimed at improving the understanding of how the processes, methods and tools of policy-making are employed to better formulate effective policies and pro-grams, and to understand the reasons why such designs are not forthcoming. However while many efforts have been made to evaluate policy design, less work has focused on program designs. This article sets out to fill this gap in knowledge of design practices in policy-making. It outlines the nature of the study of policy design with a particular focus on the nature of programs and the lessons derived from empirical experience regarding the conditions that enhance program effectiveness.